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  • 1.
    Anders, Brakestad
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Ab Initio Characterization of Conical Intersections Related to Chemiluminescence in Methylated 1,2-Dioxetanes2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 2.
    Andersson, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Theoretical study of the reactionPH3 + H → TS‡ → PH2 + H22012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3.
    Aquilante, Francesco
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, IT-40126 Bologna, Italy..
    Autschbach, Jochen
    SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA..
    Carlson, Rebecca K.
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA..
    Chibotaru, Liviu F.
    Katholieke Univ Leuven, Div Quantum & Phys Chem, Celestijnenlaan 200F, B-3001 Heverlee, Belgium.;Katholieke Univ Leuven, INPAC, Inst Nanoscale Phys & Chem, Celestijnenlaan 200F, B-3001 Heverlee, Belgium..
    Delcey, Mickael G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    De Vico, Luca
    Univ Copenhagen, Dept Chem, Univ Pk 5, DK-2100 Copenhagen O, Denmark..
    Fernández Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Ferre, Nicolas
    Univ Aix Marseille, CNRS, Inst Chim Radicalaire, Campus Etoile St Jerome Case 521,Ave Esc, F-13397 Marseille 20, France..
    Frutos, Luis Manuel
    Univ Alcala De Henares, Unidad Docente Quim Fis, E-28871 Madrid, Spain..
    Gagliardi, Laura
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA..
    Garavelli, Marco
    Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, IT-40126 Bologna, Italy.;Univ Lyon, CNRS, Ecole Normale Super Lyon, 46 Allee Italie, F-69364 Lyon 07, France..
    Giussani, Angelo
    Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, IT-40126 Bologna, Italy..
    Hoyer, Chad E.
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA..
    Li Manni, Giovanni
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA.;Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany..
    Lischka, Hans
    Texas Tech Univ, Dept Chem & Biochem, Mem Circle & Boston, Lubbock, TX 79409 USA.;Univ Vienna, Inst Theoret Chem, Wahringerstr 17, A-1090 Vienna, Austria..
    Ma, Dongxia
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA.;Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany..
    Malmqvist, Per Ake
    Lund Univ, Ctr Chem, Dept Theoret Chem, POB 124, S-22100 Lund, Sweden..
    Mueller, Thomas
    Forschungszentrum Julich, IAS, JSC, Wilhelm Johnen Str, D-52425 Julich, Germany..
    Nenov, Artur
    Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, IT-40126 Bologna, Italy..
    Olivucci, Massimo
    Univ Siena, Dept Biotechnol Chem & Pharm, Via Aldo Moro 2, I-53100 Siena, Italy.;Bowling Green State Univ, Dept Chem, 141 Overman Hall, Bowling Green, OH 43403 USA.;Univ Strasbourg, Inst Phys & Chim Mat Strasbourg, CNRS UMR 7504, 23 Rue Loess, F-67034 Strasbourg, France.;Univ Strasbourg, Labex NIE, CNRS, UMR 7504, 23 Rue Loess, F-67034 Strasbourg, France.;Hebrew Univ Jerusalem, Inst Chem, Fritz Haber Ctr Mol Dynam, IL-91904 Jerusalem, Israel..
    Pedersen, Thomas Bondo
    Univ Oslo, Dept Chem, Ctr Theoret & Computat Chem, POB 1033 Blindern, N-0315 Oslo, Norway..
    Peng, Daoling
    S China Normal Univ, Coll Chem & Environm, Guangzhou 510006, Guangdong, Peoples R China..
    Plasser, Felix
    Univ Vienna, Inst Theoret Chem, Wahringerstr 17, A-1090 Vienna, Austria..
    Pritchard, Ben
    SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA..
    Reiher, Markus
    ETH, Phys Chem Lab, Vladimir Prelog Weg 2, CH-8093 Zurich, Switzerland..
    Rivalta, Ivan
    Univ Lyon, CNRS, Ecole Normale Super Lyon, 46 Allee Italie, F-69364 Lyon 07, France..
    Schapiro, Igor
    Univ Strasbourg, Inst Phys & Chim Mat Strasbourg, CNRS UMR 7504, 23 Rue Loess, F-67034 Strasbourg, France.;Univ Strasbourg, Labex NIE, CNRS, UMR 7504, 23 Rue Loess, F-67034 Strasbourg, France..
    Segarra-Marti, Javier
    Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, IT-40126 Bologna, Italy..
    Stenrup, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Truhlar, Donald G.
    Univ Minnesota, Inst Supercomp, Dept Chem, Minneapolis, MN 55455 USA.;Univ Minnesota, Chem Theory Ctr, Minneapolis, MN 55455 USA..
    Ungur, Liviu
    Katholieke Univ Leuven, Div Quantum & Phys Chem, Celestijnenlaan 200F, B-3001 Heverlee, Belgium.;Katholieke Univ Leuven, INPAC, Inst Nanoscale Phys & Chem, Celestijnenlaan 200F, B-3001 Heverlee, Belgium..
    Valentini, Alessio
    Univ Siena, Dept Biotechnol Chem & Pharm, Via Aldo Moro 2, I-53100 Siena, Italy..
    Vancoillie, Steven
    Lund Univ, Ctr Chem, Dept Theoret Chem, POB 124, S-22100 Lund, Sweden..
    Veryazov, Valera
    Lund Univ, Ctr Chem, Dept Theoret Chem, POB 124, S-22100 Lund, Sweden..
    Vysotskiy, Victor P.
    Lund Univ, Ctr Chem, Dept Theoret Chem, POB 124, S-22100 Lund, Sweden..
    Weingart, Oliver
    Univ Dusseldorf, Inst Theoret Chem & Computerchem, Univ Str 1, D-40225 Dusseldorf, Germany..
    Zapata, Felipe
    Univ Alcala De Henares, Unidad Docente Quim Fis, E-28871 Madrid, Spain..
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Molcas 8: New capabilities for multiconfigurational quantum chemical calculations across the periodic table2016In: Journal of Computational Chemistry, ISSN 0192-8651, E-ISSN 1096-987X, Vol. 37, no 5, p. 506-541Article in journal (Refereed)
    Abstract [en]

    In this report, we summarize and describe the recent unique updates and additions to the Molcas quantum chemistry program suite as contained in release version 8. These updates include natural and spin orbitals for studies of magnetic properties, local and linear scaling methods for the Douglas-Kroll-Hess transformation, the generalized active space concept in MCSCF methods, a combination of multiconfigurational wave functions with density functional theory in the MC-PDFT method, additional methods for computation of magnetic properties, methods for diabatization, analytical gradients of state average complete active space SCF in association with density fitting, methods for constrained fragment optimization, large-scale parallel multireference configuration interaction including analytic gradients via the interface to the Columbus package, and approximations of the CASPT2 method to be used for computations of large systems. In addition, the report includes the description of a computational machinery for nonlinear optical spectroscopy through an interface to the QM/MM package Cobramm. Further, a module to run molecular dynamics simulations is added, two surface hopping algorithms are included to enable nonadiabatic calculations, and the DQ method for diabatization is added. Finally, we report on the subject of improvements with respects to alternative file options and parallelization.

  • 4.
    Aquilante, Francesco
    et al.
    Univ Bologna, Dipartimento Chim G Ciamician, Bologna, Italy..
    Delcey, Mickael G.
    Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA USA.;Univ Calif Berkeley, Dept Chem, Kenneth S Pitzer Ctr Theoret Chem, Berkeley, CA 94720 USA..
    Pedersen, Thomas Bondo
    Univ Oslo, Dept Chem, Ctr Theoret & Computat Chem, Oslo, Norway..
    Fernández Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Uppsala Univ, Dept Chem Angstrom, Theoret Chem Programme, Uppsala, Sweden..
    Inner projection techniques for the low-cost handling of two-electron integrals in quantum chemistry2017In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 115, no 17-18, p. 2052-2064Article in journal (Refereed)
    Abstract [en]

    The density-fitting technique for approximating electron-repulsion integrals relies on the quality of auxiliary basis sets. These are commonly obtained through data fitting, an approach that presents some shortcomings. On the other hand, it is possible to derive auxiliary basis sets by removing elements from the product space of both contracted and primitive orbitals by means of a particular form of inner projection technique that has come to be known as Cholesky decomposition (CD). This procedure allows for on-the-fly construction of auxiliary basis sets that may be used in conjunction with any quantum chemical method, i.e. unbiased auxiliary basis sets. One key feature of these sets is that they represent the electron-repulsion integral matrix in atomic orbital basis with an accuracy that can be systematically improved. Another key feature is represented by the fact that locality of fitting coefficients is obtained even with the long-ranged Coulomb metric, as result of integral accuracy. Here we report on recent advances in the development of the CD-based density fitting technology. In particular, the implementation of analytical gradients algorithms is reviewed and the present status of local formulations - potentially linear scaling - is analysed in detail.

  • 5.
    Aquilante, Francesco
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Pedersen, Thomas Bondo
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Veryazov, Valera
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    MOLCAS—a software for multiconfigurational quantum chemistry calculations2013In: Wiley Interdisciplinary Reviews: Computational Molecular Science, ISSN 1759-0876, Vol. 3, no 2, p. 143-149Article in journal (Refereed)
    Abstract [en]

    At variance, with most of the quantum chemistry software presently available, MOLCAS is a package that is specialized in multiconfigurational wave function theory (MC-WFT) rather than density functional theory (DFT). Given the much higher algorithmic complexity of MC-WFT versus DFT, an extraordinary effort needs to be made from the programming point of view to achieve state-of-the-art performance for large-scale calculations. In particular, a robust and efficient implementation of the Cholesky decomposition techniques for handling two-electron integrals has been developed which is unique to MOLCAS. Together with this 'Cholesky infrastructure', a powerful and multilayer graphical and scripting user interface is available, which is an essential ingredient for the setup of MC-WFT calculations. These two aspects of the MOLCAS software constitute the focus of the present report.

  • 6.
    Aspuru-Guzik, Alan
    et al.
    Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA.;Canadian Inst Adv Res CIFAR, Toronto, ON M5G 1Z8, Canada..
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Uppsala Univ, Theoret Chem Programme, Dept CUppsala Univ, Uppsala Ctr Computat Chem UC3, Box 518, S-75120 Uppsala, Sweden..
    Reiher, Markus
    Swiss Fed Inst Technol, Phys Chem Lab, Vladimir Prelog Weg 2, CH-8093 Zurich, Switzerland..
    The Matter Simulation (R)evolution2018In: ACS CENTRAL SCIENCE, ISSN 2374-7943, Vol. 4, no 2, p. 144-152Article in journal (Refereed)
    Abstract [en]

    To date, the program for the development of methods and models for atomistic and continuum simulation directed toward chemicals and materials has reached an incredible degree of sophistication and maturity. Currently, one can witness an increasingly rapid emergence of advances in computing, artificial intelligence, and robotics. This drives us to consider the future of computer simulation of matter from the molecular to the human length and time scales in a radical way that deliberately dares to go beyond the foreseeable next steps in any given discipline. This perspective article presents a view on this future development that we believe is likely to become a reality during our lifetime.

  • 7.
    Atsumi, Michiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Gonzalez, Leticia
    Gourlaouen, Christophe
    Daniel, Chantal
    Ab initio and DFT analysis of the low-lying electronic states of metal dihalides: quantum chemical calculations on the neutral BrMCl (M = Cu, Ag, Au)2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 25, p. 10151-10157Article in journal (Refereed)
    Abstract [en]

    The electronic configuration of the electronic ground and low-lying doublet excited states of neutral metal dihalides BrMCl (M = Cu, Ag, Au) has been investigated on the basis of CASSCF/CASPT2 methods taking into account scalar relativistic effects. A preliminary study of the electronic problem in BrAgCl, based on DFT and CASSCF/CASPT2 approaches and using various basis sets, namely relativistic all-electron basis sets, effective core potentials and ab initio model potentials (AIMP), as well as non-relativistic AIMP is discussed. It is shown that single-determinant methods are not flexible enough to describe the bonding of the neutral species in the electronic ground state regardless of the basis set. The failure to allocate the single electron of BrAgCl correlates with a wrong charge distribution within the complex, which is more accentuated when using pseudopotential basis sets. The inclusion of static and dynamic correlation effects by means of CASSCF/CASPT2 methods using large relativistic all-electron basis sets provides a correct qualitative picture of the electronic structure of the BrMCl series (M = Cu, Ag, Au). The spin unrestricted KS-DFT approach leads to a reasonable description of the degenerate electronic ground state ((2)Sigma/(2)Pi) bonding in these complexes with negligible spin contamination providing comparative spin densities in the series of molecules under investigation.

  • 8.
    Augusto, Felipe A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Av Prof Lineu Prestes 748, Sao Paulo, Brazil..
    Francés-Monerris, Antonio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Univ Valencia, Inst Ciencia Mol, POB 22085, Valencia 46071, Spain..
    Fdez. Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Roca-Sanjuán, Daniel
    Univ Valencia, Inst Ciencia Mol, POB 22085, Valencia 46071, Spain..
    Bastos, Erick L.
    Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Av Prof Lineu Prestes 748, Sao Paulo, Brazil..
    Baader, Wilhelm J.
    Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Av Prof Lineu Prestes 748, Sao Paulo, Brazil..
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Mechanism of activated chemiluminescence of cyclic peroxides: 1,2-dioxetanes and 1,2-dioxetanones2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 5, p. 3955-3962Article in journal (Refereed)
    Abstract [en]

    Almost all chemiluminescent and bioluminescent reactions involve cyclic peroxides. The structure of the peroxide and reaction conditions determine the quantum efficiency of light emission. Oxidizable fluorophores, the so-called activators, react with 1,2-dioxetanones promoting the former to their first singlet excited state. This transformation is inefficient and does not occur with 1,2-dioxetanes; however, they have been used as models for the efficient firefly bioluminescence. In this work, we use the SA-CASSCF/CASPT2 method to investigate the activated chemiexcitation of the parent 1,2-dioxetane and 1,2-dioxetanone. Our findings suggest that ground state decomposition of the peroxide competes efficiently with the chemiexcitation pathway, in agreement with the available experimental data. The formation of non-emissive triplet excited species is proposed to explain the low emission efficiency of the activated decomposition of 1,2-dioxetanone. Chemiexcitation is rationalized considering a peroxide/activator supermolecule undergoing an electron-transfer reaction followed by internal conversion.

  • 9.
    Azimi Mousolou, Vahid
    et al.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Canali, Carlo M.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Non-Abelian off-diagonal geometric phases in nano-engineered four-qubit systems2013In: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 103, no 6, p. 60011-Article in journal (Refereed)
    Abstract [en]

    The concept of off-diagonal geometric phase (GP) has been introduced in order to recover interference information about the geometry of quantal evolution where the standard GPs are not well-defined. In this Letter, we propose a physical setting for realizing non-Abelian off- diagonal GPs. The proposed non-Abelian off-diagonal GPs can be implemented in a cyclic chain of four qubits with controllable nearest-neighbor interactions. Our proposal seems to be within reach in various nano-engineered systems and therefore opens up for first experimental test of the non-Abelian off-diagonal GP. 

  • 10.
    Azimi Mousolou, Vahid
    et al.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Canali, Carlo M.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Centre for Quantum Technologies, NUS, Singapore.
    Unifying Geometric Entanglement and Geometric Phase in a Quantum Phase Transition2013In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 88, no 1, p. 012310-Article in journal (Refereed)
    Abstract [en]

    Geometric measure of entanglement and geometric phase have recently been used to analyze quantum phase transition in the XY spin chain. We unify these two approaches by showing that the geometric entanglement and the geometric phase are respectively the real and imaginary parts of a complex-valued geometric entanglement, which can be investigated in typical quantum interferometry experiments. We argue that the singular behavior of the complex-value geometric entanglement at a quantum critical point is a characteristic of any quantum phase transition, by showing that the underlying mechanism is the occurrence of level crossings associated with the underlying Hamiltonian.

  • 11.
    Azimi Mousolou, Vahid
    et al.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Canali, Carlo M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Theoretical Chemistry. School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Universal Non-adiabatic Holonomic Gates in Quantum Dots and Single-Molecule Magnets2014In: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 16, article id 013029Article in journal (Refereed)
    Abstract [en]

    Geometric manipulation of a quantum system offers a method for fast, universal, and robust quantum information processing. Here, we propose a scheme for universal all-geometric quantum computation using non-adiabatic quantum holonomies. We propose three different realizations of the scheme based on an unconventional use of quantum dot and single-molecule magnet devices, which offer promising scalability and robust efficiency. 

  • 12.
    Azimi Mousolou, Vahid
    et al.
    School of Computer Science, Physics and Mathematics, Linnaeus Univ., Sweden.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Non-Abelian geometric phases in a system of coupled quantum bits2014In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 89, no 2, p. 022117-Article in journal (Refereed)
    Abstract [en]

    A common strategy to measure the Abelian geometric phase for a qubit is to let it evolve along an `orange slice' shaped path connecting two antipodal points on the Bloch sphere by two different semi-great circles. Since the dynamical phases vanish for such paths, this allows for direct interference measurement of the geometric phase. Here, we generalize the orange slice setting to the non-Abelian case. The proposed method to measure the non-Abelian geometric phase can be implemented in a cyclic chain of four qubits with controllable nearest-neighbor interactions.

  • 13.
    Banerjee, D.
    et al.
    ETH, Zurich, Switzerland..
    Biraben, F.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Charlton, M.
    Swansea Univ, Swansea, W Glam, Wales..
    Clade, P.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Comini, P.
    Ctr Spectrometrie Nucl & Spectrometrie Masse, Orsay, France.;ETH, Zurich, Switzerland..
    Crivelli, P.
    ETH, Zurich, Switzerland..
    Dalkarov, O.
    PN Lebedev Phys Inst, Moscow, Russia..
    Debu, P.
    CEA Saclay, IRFU, Saclay, France..
    Dodd, L.
    Swansea Univ, Swansea, W Glam, Wales..
    Douillet, A.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France.;Univ Evry, Comue Paris Saclay, Evry, France..
    Dufour, G.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Dupre, P.
    Inst Phys & Chem Res, Wako, Saitama, Japan..
    Eriksson, S.
    Swansea Univ, Swansea, W Glam, Wales..
    Froelich, Piotr
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Grandemange, P.
    CERN, CH-1211 Geneva 23, Switzerland..
    Guellati, S.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Guerout, R.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Heinrich, M.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Hervieux, P. -A
    Hilico, L.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France.;Univ Evry, Comue Paris Saclay, Evry, France..
    Husson, A.
    Ctr Spectrometrie Nucl & Spectrometrie Masse, Orsay, France..
    Indelicato, P.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Jonsell, S.
    Stockholm Univ, Stockholm, Sweden..
    Karr, J. -P
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France.
    Khabarova, K.
    PN Lebedev Phys Inst, Moscow, Russia..
    Kim, S. K.
    Seoul Natl Univ, Seoul, South Korea..
    Kim, Y.
    Inst for Basic Sci Korea, Daejon, South Korea..
    Kolachevsky, N.
    PN Lebedev Phys Inst, Moscow, Russia..
    Kuroda, N.
    Univ Tokyo, Inst Phys, Komaba, Japan..
    Lambrecht, A.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Leite, A. M. M.
    CEA Saclay, IRFU, Saclay, France..
    Liszkay, L.
    CEA Saclay, IRFU, Saclay, France..
    Lotrus, P.
    CEA Saclay, IRFU, Saclay, France..
    Lunney, D.
    Ctr Spectrometrie Nucl & Spectrometrie Masse, Orsay, France..
    Madsen, N.
    Swansea Univ, Swansea, W Glam, Wales..
    Manfredi, G.
    Inst Phys & Chim Mat Strasbourg, Strasbourg, France..
    Mansouli, B.
    CEA Saclay, IRFU, Saclay, France..
    Matsuda, Y.
    Univ Tokyo, Inst Phys, Komaba, Japan..
    Mohri, A.
    Kyoto Univ, Kyoto, Japan..
    Mornacchi, G.
    CERN, CH-1211 Geneva 23, Switzerland..
    Nesvizhevsky, V.
    Inst Laue Langevin, Grenoble, France..
    Nez, F.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Perez, P.
    CEA Saclay, IRFU, Saclay, France..
    Regenfus, C.
    ETH, Zurich, Switzerland..
    Rey, J. -M
    Reymond, J. -M
    Rousse, J-Y
    CEA Saclay, IRFU, Saclay, France..
    Reynaud, S.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Rubbia, A.
    ETH, Zurich, Switzerland..
    Sacquin, Y.
    CEA Saclay, IRFU, Saclay, France..
    Schmidt-Kaler, F.
    Johannes Gutenberg Univ Mainz, Mainz, Germany..
    Sillitoe, N.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Staszczak, M.
    Natl Ctr Nucl Res, Otwock, Poland..
    Torii, H.
    Univ Tokyo, Inst Phys, Komaba, Japan..
    Heinrich, J. M.
    ENS PSL Res Univ, UPMC Sorbonne Univ, Lab Kastler Brossel, CNRS,Coll France, Paris, France..
    Vallage, B.
    CEA Saclay, IRFU, Saclay, France..
    Valdes, M.
    Inst Phys & Chim Mat Strasbourg, Strasbourg, France..
    van der Werf, D. P.
    CEA Saclay, IRFU, Saclay, France.;Swansea Univ, Swansea, W Glam, Wales..
    Voronin, A.
    PN Lebedev Phys Inst, Moscow, Russia..
    Walz, J.
    Johannes Gutenberg Univ Mainz, Mainz, Germany..
    Wolf, S.
    Johannes Gutenberg Univ Mainz, Mainz, Germany..
    Wronka, S.
    Natl Ctr Nucl Res, Otwock, Poland..
    Yamazaki, Y.
    Inst Phys & Chem Res, Wako, Saitama, Japan..
    Towards a test of the Weak Equivalence Principle of gravity using anti-hydrogen at CERN2016In: 2016 Conference On Precision Electromagnetic Measurements (CPEM 2016), 2016Conference paper (Refereed)
    Abstract [en]

    The aim of the GBAR (Gravitational Behavior of Antimatter at Rest) experiment is to measure the free fall acceleration of an antihydrogen atom, in the terrestrial gravitational field at CERN and therefore test the Weak Equivalence Principle with antimatter. The aim is to measure the local gravity with a 1% uncertainty which can be reduced to few parts of 10(-3).

  • 14. Barata-Morgado, Rute
    et al.
    Luz Sanchez, M.
    Fernández Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Corchado, Jose C.
    Elena Martin, M.
    Munoz-Losa, Aurora
    Aguilar, Manuel A.
    Theoretical study of the conformational equilibrium of 1,4-dioxane in gas phase, neat liquid, and dilute aqueous solutions2013In: Theoretical Chemistry accounts, ISSN 1432-881X, E-ISSN 1432-2234, Vol. 132, no 10, p. 1390-Article in journal (Refereed)
    Abstract [en]

    The conformational equilibrium of 1,4-dioxane in the gas phase, in the pure liquid, and in aqueous solution has been studied by means of the Average Solvent Electrostatic Potential from Molecular Dynamics (ASEP/MD) method and the Integral Equation Formalism for the Polarizable Continuum Model (IEF-PCM). The dioxane molecule was described at the DFT(B3LYP)/aug-cc-pVTZ level. In the three phases, the equilibrium is almost completely shifted toward the chair conformer, with populations of the twist-boat conformers lower than 0.01 %. The equilibrium is dominated by the internal energy of the molecule, as the solute-solvent interaction free energies are very similar in the three conformers considered (chair, 1,4 twist-boat, and 2,5 twist-boat). In the pure liquid, where the dioxane-dioxane interaction is dominated by the Lennard-Jones term, the structure is characteristic of a van der Waals liquid. However, the decrease in the C-H distance from gas phase to solution, the increase in the C-H vibrational frequencies, and the presence of a shoulder in the O-Haxial pair radial distribution function point to the presence of a weak C-H-O hydrogen bond. The analysis of the occupancy maps of water oxygen and hydrogen atoms around the 1,4-dioxane molecule confirms this conclusion. Contrary to what is found in small water-dioxane clusters, in the liquid, there is a preference for oxygen atoms to interact with axial hydrogen atoms to form C-H-O hydrogen bonds. Comparison of ASEP/MD and IEF-PCM results indicates that including specific interactions is very important for an adequate description of the solute-solvent interaction; however, the influence of these interactions does not translate in changes in the relative stability of the conformers because it cancels out when energy differences are calculated.

  • 15.
    Bengtson, Charlotta
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Nonlocality in biomolecular systems2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 16.
    Bengtson, Charlotta
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Quantum Resources for Efficient Excitation Energy Transfer in Natural and Artificial Pigment-Protein Molecular Aggregates2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Recently, long-lasting quantum effects in a number of photosynthetic complexes, which are pigment-protein molecular aggregates (PPMAs), were experimentally verified. These findings created an interest in trying to connect the known highly efficient excitation energy transfer (EET) in these systems to the existence of quantum effects such as quantum coherence and quantum correlations. It also raised the question of how these sensitive quantum effects can survive in such a macroscopic system.

    This thesis explores the existence and possible role of quantum effects in the EET in PPMAs. These systems can be modeled as non-Markovian open quantum systems and quantum effects can be investigated and quantified by methods developed in quantum information theory.

    Firstly, it is found that quantum nonlocal correlations in the EET in the Fenna-Matthews-Olson complex - a PPMA found in nature - are unlikely to exist when the initial excitation occurs in a natural manner. When the initial excitation occurs in an artificial manner by localization of the excitation on one pigment, nonlocal correlations exist on a short time scale. It is further found that in order for nonlocal correlations to be preserved in such a system, the excitation must be trapped on two pigments at the time and these pigments must not interact strongly with other pigments in the complex.

    Secondly, it is shown that quantum coherence is not in general a resource for efficient EET in model systems consisting of a network of pigments; systems optimized with respect to the amount of coherence do not coincide with systems with optimal EET efficiency between two end-site pigments.

    Thirdly, it is found that environmental effects and system-environment interactions can be tuned to optimize the EET efficiency in model PPMAs. The features of optimal environments highly depends on the structure of the pigment system and in particular, the relationship between the pigments excitation energies. It is further shown that a non-Markovian dynamics cannot be connected to an increased EET efficiency in these systems.

    List of papers
    1. Quantum nonlocality in the excitation energy transfer in the Fenna-Matthews-Olson complex
    Open this publication in new window or tab >>Quantum nonlocality in the excitation energy transfer in the Fenna-Matthews-Olson complex
    2016 (English)In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 116, p. 1763-1771Article in journal (Refereed) Published
    Abstract [en]

    The Fenna-Matthews-Olson (FMO) complex - a pigment protein complex involved in photosynthesis in green sulfur bacteria - is remarkably efficient in transferring excitation energy from light harvesting antenna molecules to a reaction center. Recent experimental and theoretical studies suggest that quantum coherence and entanglement may play a role in this excitation energy transfer (EET). We examine whether bipartite quantum nonlocality, a property that expresses a stronger-than-entanglement form of correlation, exists between different pairs of chromophores in the FMO complex when modeling the EET by the hierarchically coupled equations of motion method. We compare the results for nonlocality with the amount of bipartite entanglement in the system. In particular, we analyze in what way these correlation properties are affected by different initial conditions. It is found that bipartite nonlocality only exists when the initial conditions are chosen in an unphysiological manner and probably is absent when considering the EET in the FMO complex in its natural habitat. It is also seen that nonlocality and entanglement behave quite differently in this system. In particular, for localized initial states, nonlocality only exists on a very short time scale and then drops to zero in an abrupt manner. As already known from previous studies, quantum entanglement between chromophore pairs on the other hand is oscillating and exponentially decaying and follow thereby a pattern more similar to the chromophore population dynamics. The abrupt disappearance of nonlocality in the presence of nonvanishing entanglement is a phenomenon we call nonlocality sudden death; a striking manifestation of the difference between these two types of correlations in quantum systems. 

    Keywords
    Photosynthesis, quantum nonlocality, open quantum systems
    National Category
    Other Physics Topics Theoretical Chemistry
    Research subject
    Physics with specialization in Quantum Chemistry; Biology
    Identifiers
    urn:nbn:se:uu:diva-246119 (URN)10.1002/qua.25221 (DOI)000385587200001 ()
    Funder
    Swedish Research Council, D0413201eSSENCE - An eScience CollaborationSwedish National Infrastructure for Computing (SNIC), snic2014-3-66
    Available from: 2015-03-02 Created: 2015-03-02 Last updated: 2018-01-19Bibliographically approved
    2. Nonlocality in the Fenna-Matthews-Olson complex: Using Nature for learning about nonlocality preservation in a multi-qubit open system
    Open this publication in new window or tab >>Nonlocality in the Fenna-Matthews-Olson complex: Using Nature for learning about nonlocality preservation in a multi-qubit open system
    (English)Manuscript (preprint) (Other academic)
    Keywords
    Quantum nonlocality, Quantum coherence, Open quantum systems
    National Category
    Natural Sciences
    Research subject
    Chemistry with specialization in Quantum Chemistry
    Identifiers
    urn:nbn:se:uu:diva-339463 (URN)
    Available from: 2018-01-18 Created: 2018-01-18 Last updated: 2018-03-06
    3. The role of quantum coherence in dimer and trimer excitation energy transfer
    Open this publication in new window or tab >>The role of quantum coherence in dimer and trimer excitation energy transfer
    2017 (English)In: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 19, article id 113015Article in journal (Refereed) Published
    Abstract [en]

    Recent progress in resource theory of quantum coherence has resulted in measures to quantify coherence in quantum systems. Especially, the l1-norm and relative entropy of coherence have been shown to be proper quantifiers of coherence and have been used to investigate coherence properties in different operational tasks. Since long-lasting quantum coherence has been experimentally confirmed in a number of photosynthetic complexes, it has been debated if and how coherence is connected to the known efficiency of population transfer in such systems. In this study, we investigate quantitatively the relationship between coherence, as quantified by l1 norm and relative entropy of coherence, and efficiency, as quantified by fidelity, for population transfer between end-sites in a network of two-level quantum systems. In particular, we use the coherence averaged over the duration of the population transfer in order to carry out a quantitative comparision between coherence and fidelity. Our results show that although coherence is a necessary requirement for population transfer, there is no unique relation between coherence and the efficiency of the transfer process.

    Keywords
    Quantum coherence, energy transport
    National Category
    Other Physics Topics
    Research subject
    Physics with spec. in Atomic, Molecular and Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-327295 (URN)10.1088/1367-2630/aa916b (DOI)000415196900003 ()
    Funder
    Swedish Research Council, D0413201Swedish National Infrastructure for Computing (SNIC), snic2017-7-17
    Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2018-02-21Bibliographically approved
    4. Environmental design principles for efficient excitation energy transfer in dimer and trimer pigment-protein molecular aggregates and the relation to non-Markovianity
    Open this publication in new window or tab >>Environmental design principles for efficient excitation energy transfer in dimer and trimer pigment-protein molecular aggregates and the relation to non-Markovianity
    (English)In: QuantumArticle in journal (Refereed) Submitted
    Abstract [en]

    Lately there has been an interest in studying the effects and mechanisms of environment-assisted quantum transport, especially in the context of excitation energy transfer (EET) in pigment-protein molecular aggregates. Since these systems can be seen as open quantum systems where the dynamics is within the non-Markovian regime, the effect of non-Markovianity on efficient EET as well as its role in preserving quantum coherence and correlations has also been investigated in recent works. In this study, we explore optimal environments for efficient EET between end sites in a number of dimer and trimer model pigment-protein molecular aggregates when the EET dynamics is modeled by the HEOM-method. For these optimal environmental parameters, we further quantify the non-Markovianity by the BLP-measure to elucidate its possible connection to efficient EET. We also quantify coherence in the pigment systems by means of the measure l1-norm of coherence to analyze its interplay with environmental effects when EET efficiency is maximal. Our aim is to investigate possible environmental design principles for achieving efficient EET in model pigment-protein molecular aggregates and to determine whether non-Markovianity is a possible underlying resource in such systems. We find that the structure of the system Hamiltonian (i.e., the pigment Hamiltonian parameter space) and especially, the relationship between the site excitation energies, determines whether one of two specific environmental regimes is the most beneficial in promoting efficient EET in these model systems. In the first regime, optimal environmental conditions are such that the EET dynamics in the system is left as coherent as possible. In the second regime, the most advantageous role of the environment is to drive the system towards equilibrium as fast as possible. In reality, optimal environmental conditions may involve a combination of these two effects. We cannot establish a relation between efficient EET and non-Markovianity, i.e., non-Markovianity cannot be regarded as a resource in the systems investigated in this study. 

    Keywords
    Excitation energy transfer, Quantum coherence, Non-Markovianity
    National Category
    Natural Sciences
    Research subject
    Chemistry with specialization in Quantum Chemistry
    Identifiers
    urn:nbn:se:uu:diva-339462 (URN)
    Available from: 2018-01-18 Created: 2018-01-18 Last updated: 2018-03-06
  • 17.
    Bengtson, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Ahlkvist, Mikaela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Ekeroth, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Nilsen-Moe, Astrid
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Proos Vedin, Nathalie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Rodiuchkina, Katerina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Ye, Sofie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lundberg, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Working as Partners: Course Development by a Student–Teacher Team2017In: International Journal for the Scholarship of Teaching & Learning, ISSN 1931-4744, E-ISSN 1931-4744, Vol. 11, no 2, article id Article 6Article in journal (Refereed)
    Abstract [en]

    A first-year undergraduate course at Uppsala University has been redesigned in a process exploring differentlevels of student participation. In the first part of the project, the student voice was heard through interviewsfocusing on the role of the course in the degree program. In the second part, a student-teacher team wasformed to develop course curriculum and teaching material in partnership. Among the implemented changeswere new seminars focusing on conceptual understanding, redesign of all lectures to include active studentparticipation, and a change of the course literature. The redesigned course significantly increased studentsatisfaction compared to previous years. Important success factors were involvement of the studentorganization to promote the project, institutional support, early selection of concrete development tasks, andallowing team members to choose what they wanted to develop according to their own expertise.

  • 18.
    Bengtson, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Lundberg, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Studentmedverkan i utvecklingen av kursen ”Fysik för kemister”2016In: För pedagogisk utveckling tillsammans: Lärare och studenter som medskapare av utbildningen / [ed] Katarina Andreasen och Maria Magnusson, Uppsala: Uppsala universitet, 2016, p. 20-26Conference paper (Other academic)
    Abstract [sv]

    Vi utforskar olika nivåer av studentmedverkan i utvecklingen av kursen ’Fysik för kemister’ på kandidatprogrammet i kemi vid Uppsala universitet. Målet med kursen är att ge alla studenter, även de med en självupplevt svag fysikbakgrund, en god grund för framtida studier i kemi. För att nå dit vill vi bjuda in en bred grupp av studenter att bli medskapare av en bättre kurs. Projektets första steg var att intervjua sex studenter i olika steg av utbildningen, fyra kvinnor och två män. Två av studenterna har redan läst hela kandidatutbildningen och har ett unikt perspektiv över vilken nytta de har haft av kursen i sin utbildning, samt vilka kunskaper de egentligen hade behövt. Resultaten från intervjuerna har använts för att skriva en ny kursplan samt att utveckla nya former av studentaktiv undervisning. Nästa steg, som fortfarande pågår, är att öka deltagandenivån genom att arbeta i en kursutvecklingsgrupp, bestående av sex studenter från olika årskurser samt två lärare.

  • 19.
    Bengtson, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    The role of quantum coherence in dimer and trimer excitation energy transfer2017In: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 19, article id 113015Article in journal (Refereed)
    Abstract [en]

    Recent progress in resource theory of quantum coherence has resulted in measures to quantify coherence in quantum systems. Especially, the l1-norm and relative entropy of coherence have been shown to be proper quantifiers of coherence and have been used to investigate coherence properties in different operational tasks. Since long-lasting quantum coherence has been experimentally confirmed in a number of photosynthetic complexes, it has been debated if and how coherence is connected to the known efficiency of population transfer in such systems. In this study, we investigate quantitatively the relationship between coherence, as quantified by l1 norm and relative entropy of coherence, and efficiency, as quantified by fidelity, for population transfer between end-sites in a network of two-level quantum systems. In particular, we use the coherence averaged over the duration of the population transfer in order to carry out a quantitative comparision between coherence and fidelity. Our results show that although coherence is a necessary requirement for population transfer, there is no unique relation between coherence and the efficiency of the transfer process.

  • 20.
    Bengtson, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Stenrup, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Sjöqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Quantum nonlocality in the excitation energy transfer in the Fenna-Matthews-Olson complex2016In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 116, p. 1763-1771Article in journal (Refereed)
    Abstract [en]

    The Fenna-Matthews-Olson (FMO) complex - a pigment protein complex involved in photosynthesis in green sulfur bacteria - is remarkably efficient in transferring excitation energy from light harvesting antenna molecules to a reaction center. Recent experimental and theoretical studies suggest that quantum coherence and entanglement may play a role in this excitation energy transfer (EET). We examine whether bipartite quantum nonlocality, a property that expresses a stronger-than-entanglement form of correlation, exists between different pairs of chromophores in the FMO complex when modeling the EET by the hierarchically coupled equations of motion method. We compare the results for nonlocality with the amount of bipartite entanglement in the system. In particular, we analyze in what way these correlation properties are affected by different initial conditions. It is found that bipartite nonlocality only exists when the initial conditions are chosen in an unphysiological manner and probably is absent when considering the EET in the FMO complex in its natural habitat. It is also seen that nonlocality and entanglement behave quite differently in this system. In particular, for localized initial states, nonlocality only exists on a very short time scale and then drops to zero in an abrupt manner. As already known from previous studies, quantum entanglement between chromophore pairs on the other hand is oscillating and exponentially decaying and follow thereby a pattern more similar to the chromophore population dynamics. The abrupt disappearance of nonlocality in the presence of nonvanishing entanglement is a phenomenon we call nonlocality sudden death; a striking manifestation of the difference between these two types of correlations in quantum systems. 

  • 21.
    Berraud-Pache, Romain
    et al.
    Univ Paris Est, Lab Modelisat & Simulat Multi Echelle, MSME, UMR CNRS 8208,UPEM, 5 Bd Descartes, F-77454 Marne La Vallee, France.
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Navizet, Isabelle
    Univ Paris Est, Lab Modelisat & Simulat Multi Echelle, MSME, UMR CNRS 8208,UPEM, 5 Bd Descartes, F-77454 Marne La Vallee, France.
    QM/MM Study of the Formation of the Dioxetanone Ring in Fireflies through a Superoxide Ion2018In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 122, no 20, p. 5173-5182Article in journal (Refereed)
    Abstract [en]

    The bioluminescence emission from fireflies is an astounding tool to mark and view cells. However, the bioluminescent mechanism is not completely deciphered, limiting the comprehension of key processes. We use a theoretical approach to study for the first time the arrival of a dioxygen molecule inside the fireflies protein and one path of the formation of the dioxetanone ring, the high-energy intermediate precursor of the bioluminescence. To describe this reaction step, a joint approach combining classical molecular dynamics (MD) simulations and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations is used. The formation of the dioxetanone ring has been studied for both singlet and triplet states with the help of MS-CASPT2 calculations. We also emphasize the role played by the proteinic environment in the formation of the dioxetanone ring. The results obtained shed some light on an important reaction step and give new insights concerning the bioluminescence in fireflies.

  • 22. Bostrom, Jonas
    et al.
    Pitonak, Michal
    Aquilante, Francesco
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Neogrady, Pavel
    Pedersen, Thomas Bondo
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Coupled Cluster and Moller-Plesset Perturbation Theory Calculations of Noncovalent Intermolecular Interactions using Density Fitting with Auxiliary Basis Sets from Cholesky Decompositions2012In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 8, no 6, p. 1921-1928Article in journal (Refereed)
    Abstract [en]

    We compute noncovalent intermolecular interaction energies for the S22 test set [Phys. Chem. Chem. Phys. 2006, 8, 1985-1993] of molecules at the Moller-Plesset and coupled cluster levels of supermolecular theory using density fitting (DF) to approximate all two-electron integrals. The error due to the DF approximation is analyzed for a range of auxiliary basis sets derived from Cholesky decomposition (CD) in conjunction with correlation consistent and atomic natural orbital valence basis sets. A Cholesky decomposition threshold of 10(-4)E(h) for full molecular CD and its one-center approximation (1C-CD) generally yields errors below 0.03 kcal/mol, whereas 10(-3)E(h) is sufficient to obtain the same level of accuracy or better with the atomic CD (aCD) and atomic compact CD (acCD) auxiliary basis sets. Comparing to commonly used predefined auxiliary basis sets, we find that while the aCD and acCD sets are larger by a factor of 2-4 with triple-zeta AO basis sets, they provide results 1-2 orders of magnitude more accurate.

  • 23. Boström, Jonas
    et al.
    Aquilante, Francesco
    Pedersen, Thomas Bondo
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Analytical gradients of Hartree-Fock exchange with density fitting approximations2013In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 9, no 1, p. 204-212Article in journal (Refereed)
    Abstract [en]

    We extend the local exchange (LK) algorithm [Aquilante, F.; Pedersen, T. B.; Lindh, R. J. Chem. Phys.2007, 126, 194106] to the calculation of analytical gradients with density fitting. We discuss the features of the screening procedure and demonstrate the possible advantages of using this formulation, which is easily interfaced to a standard integral-direct gradient code. With auxiliary basis sets obtained from Cholesky decomposition of atomic or molecular integral blocks with a decomposition threshold of 10-4Eh, typical errors due to the density fitting in bond lengths, bond angles, and dihedral angles are 0.1 pm, 0.1°, and 0.5°, respectively. The overall speedup of geometry optimizations is about 1 order of magnitude for atomic natural-orbital-type basis sets but much less pronounced for correlation-consistent basis sets.

  • 24. Boström, Jonas
    et al.
    Veryazov, Valera
    Aquilante, Francesco
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Bondo Pedersen, Thomas
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Analytical gradients of the second-order Møller–Plesset energy using Cholesky decompositions2014In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 114, no 5, p. 321-327Article in journal (Refereed)
    Abstract [en]

    An algorithm for computing analytical gradients of the second-order Møller–Plesset (MP2) energy using density fitting (DF) is presented. The algorithm assumes that the underlying canonical Hartree–Fock reference is obtained with the same auxiliary basis set, which we obtain by Cholesky decomposition (CD) of atomic electron repulsion integrals. CD is also used for the negative semidefinite MP2 amplitude matrix. Test calculations on the weakly interacting dimers of the S22 test set (Jurečka et al., Phys. Chem. Chem. Phys. 2006, 8, 1985) show that the geometry errors due to the auxiliary basis set are negligible. With double-zeta basis sets, the error due to the DF approximation in intermolecular bond lengths is better than 0.1 pm. The computational time is typically reduced by a factor of 6–7.

  • 25.
    Brändas, Erkki
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Chapter 1: The Relativistic Kepler Problem and Gödel’s Paradox2012In: Progress in Theoretical Chemistry and Physics 26. Progress in Methods and Applications: Quantum Systems in Chemistry and / [ed] K. Nishikawa et al., Heidelberg: Springer, 2012, p. 3-22Chapter in book (Refereed)
    Abstract [en]

    Employing a characteristic functional model that conscripts arrays ofoperators in terms of energy and momentum adjoined with their conjugate operatorsof time and position, we have recently derived an extended superposition principlecompatible both with quantum mechanics and Einstein’s laws of relativity.We havelikewise derived a global, universal superposition principle with the autonomouschoice to implement, when required, classical or quantum representations. Thepresent viewpoint amalgamates the microscopic and the macroscopic domainsvia abstract complex symmetric forms through suitable operator classificationsincluding appropriate boundary conditions. An important case in point comes fromthe theory of general relativity, i.e. the demand for the proper limiting order at theSchwarzschild radius. In this example, one obtains a surprising relation betweenG¨odel’s incompleteness theorem and the proper limiting behaviour of the presenttheory at the Schwarzschild singularity. In the present study, we will apply ourtheoretical formulation to the relativistic Kepler problem, recovering the celebratedresult from the theory of general relativity in the calculation of the perihelionmovement of Mercury.

  • 26.
    Brändas, Erkki
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Per-Olov Löwdin - father of quantum chemistry2017In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 115, no 17-18, p. 1995-2024Article in journal (Other academic)
    Abstract [en]

    During 2016, we celebrate the 100th anniversary of the birth of Per-Olov Lowdin. He was appointed to the first Lehrstuhl in quantum chemistry at Uppsala University in 1960. Lowdin introduced quantum chemistry as a field in its own right by formulating its goals, establishing fundamental concepts, like the correlation energy, the method of configuration interaction, reduced density matrices, natural spin orbitals, charge and bond order matrices, symmetric orthogonalisation, and generalised self-consistent fields. His exposition of partitioning technique and perturbation theory, wave and reaction operators and associated non-linear summation techniques, introduced mathematical rigour and deductive order in the interpretative organisation of the new field. He brought the first computer to Uppsala University and pioneered the initiation of electronic brains' and anticipated their significance for quantum chemistry. Perhaps his single most influential contribution to the field was his education of two generations of future faculty in quantum chemistry through Summer Schools in the Scandinavian Mountains, Winter Institutes at Sanibel Island in the Gulf of Mexico. Per-Olov Lowdin founded the book series Advances in Quantum Chemistry and the International Journal of Quantum Chemistry. The evolution of quantum chemistry is appraised, starting from a collection of cross-disciplinary applications of quantum mechanics to the technologically advanced and predominant field of today, virtually used in all branches of chemistry. The scientific work of Per-Olov Lowdin has been crucial for the development of this new important province of science. [GRAPHICS] .

  • 27.
    Brändas, Erkki
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    The Origin and Evolution of Complex Enough Systems in Biology2017Conference paper (Refereed)
    Abstract [en]

    Recent criticisms of Neo-Darwinism are considered and disputed within the setting of recent advances in chemical physics. A related query, viz., the ontological thesis, that everything is physical, confronts a crucial test on the validity of reductionism as a fundamental approach to science.  While traditional ‘physicalism’ interprets evolution as a sequence of physical accidents governed by the second law of thermodynamics, the concepts of biology concern processes that owe their goal-directedness to the influence of an evolved program. This disagreement is met by unifying basic aspects of chemistry and physics, formulating the Correlated Dissipative Ensemble, CDE, as a characterization of a ‘complex enough systems’, CES, in biology. The latter entreats dissipative dynamics; non-Hermitian quantum mechanics together with modern quantum statistics thereby establish a precise spatio-temporal order of significance for living systems. The CDE grants a unitary transformation structure that comprises communication protocols of embedded Poisson statistics for molecular recognition and cellular differentiation, providing cell-hierarchies in the organism. The present conception of evolution, founded on communication with a built-in self-referential order, offers a valid argument in favour of Neo-Darwinism, providing an altogether solid response and answer to the criticisms voiced above.

  • 28.
    Brändas, Erkki
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    The Statement of Goals of the International Society for Theoretical Chemical Physics2014In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 114, p. 961-962Article in journal (Refereed)
  • 29.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    A Comment on Background Independence in Quantum Theory2016In: Journal of the Chinese Chemical Society (Taipei), ISSN 0009-4536, E-ISSN 2192-6549, Vol. 63, no 1, p. 11-19Article in journal (Refereed)
    Abstract [en]

    In this communication we take up the significance and purpose of selecting the proper coordinate system from the flat space-time of non-relativistic theories to the quantum theoretic formulation of general relativity. The universal background problem is straight forwardly framed as a momentum-energy portrait in nexus with its space-time conjugates. The description is based on operator matrix algebra, where the related analogue of the secular equation yields a Klein-Gordon type equation and the associated Minkowski eigentime element. The energy-momentum and their conjugate partners are represented by spaces that have (+,-) signatures. The general theory implicates both non-zero- and zero rest-mass entities, and it is proved that the conjugate relationship between energy and time provide a simple derivation of the Schwarzschild line element for the case of a gravitational field outside a spherical non-rotational uncharged mass. This result, indicating the appearance of a black hole as a true singularity in the energy-time formulation, and obtained as a direct consequence of their conjugate relationship, manifests background independence in concert with Einstein's equivalence principle. Inducing a reformulation of the Lorentz Transformation respecting the indefinite Minkowski metric, displays an interesting relation between complex dilations and indefinite metric spaces, validating the complex symmetric ansatz.

  • 30.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    A Zero Energy Universe Scenario: From Unstable Chemical States to Biological Evolution and Cosmological Order2015In: Frontiers In Quantum Methods And Applications In Chemistry And Physics / [ed] Nascimento, MAC; Maruani, J; Brandas, EJ; DelgadoBarrio, G, Heidelberg: Springer, 2015, Vol. A29, p. 247-284Conference paper (Refereed)
    Abstract [en]

     A Zero-Energy Universe Scenario (ZEUS) is portrayed and its implications are examined and clarified. The formulation is based on the algebra of observables, e.g. the momentum-energy and their canonical conjugate partner space-time. Operators represent them in quantum theory and classical canonical variables in nonquantum applications. Conjugate operator/variable arrays impart a united edifice for a zero-energy universe scenario, which corresponds to using a non-positive definite metric for the manifestation of unstable states as recently employed in the field of chemical physics. Analogous formulations within a general complex symmetric setting provide a compelling analogy between Einstein s theory of general gravity and Gödel s first incompleteness theorem. This scenario brings together up-to-date theories in chemical physics with modern research in biology, physics, and astronomy. This unification establishes an edifice for the various arrows of time as well as authenticates Darwin s Paradigm of Evolution from the microscopic realm to the cosmological domain.

  • 31.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Arrows of Time and Fundamental Symmetries in Chemical Physics2013In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 113, no 3, p. 173-184Article in journal (Refereed)
    Abstract [en]

    The field of chemical and physical processes, using principal microscopic techniques, should today allegedly be identified as a fundamental branch of physics. The discipline, by tradition known as chemical physics, is undergoing rapid progress. This assessment, illustrated by the advances presented at this Congress, is characterized by modern developments and novel trends with a concrete bearing on original theoretical understanding, with the possibility to go beyond traditional interpretations and explanations. In this vein, we do not only consider nonrelativistic treatments of various types of molecules including interactions between these and polymers, theoretical examinations of chemical reactions, surface states and interface states, disordered phenomena etc., but also recent progress together with non-Hermitian extensions to quantum mechanics and statistical mechanics. The latter leads to a united edifice of theoretical constructions including the law of self-reference, which emerges in analogy with the illustrious Gödel theorem(s) of mathematical logic, that is, the assertion of the inherent limitations of all nontrivial axiomatic systems. The current development begets the foundation of temporal processes and associated invariance principles including the valuation of the various arrows of time. The present conjugate operator array formulation supports the possible gravitational origin of molecular chirality and other principal symmetry violations.

  • 32.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Arrows of time and fundamental symmetries in chemical physics2013In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 113, no 3, p. 173-184Article in journal (Refereed)
    Abstract [en]

    The field of chemical and physical processes, using principal microscopic techniques, should today allegedly be identified as a fundamental branch of physics. The discipline, by tradition known as chemical physics, is undergoing rapid progress. This assessment, illustrated by the advances presented at this Congress, is characterized by modern developments and novel trends with a concrete bearing on original theoretical understanding, with the possibility to go beyond traditional interpretations and explanations. In this vein, we do not only consider nonrelativistic treatments of various types of molecules including interactions between these and polymers, theoretical examinations of chemical reactions, surface states and interface states, disordered phenomena etc., but also recent progress together with non-Hermitean extensions to quantum mechanics and statistical mechanics. The latter leads to a united edifice of theoretical constructions including the law of self-reference, which emerges in analogy with the illustrious Godel theorem(s) of mathematical logic, that is, the assertion of the inherent limitations of all nontrivial axiomatic systems. The current development begets the foundation of temporal processes and associated invariance principles including the valuation of the various arrows of time. The present conjugate operator array formulation supports the possible gravitational origin of molecular chirality and other principal symmetry violations.

  • 33.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Dissipative Structures and Biological Evolution2013In: Understanding Complex Systems: Without Bounds: A Scientific Canvas of Nonlinearityand Complex Dynamics, Understanding Complex Systems, / [ed] Ramon G. Rubio et al., Berlin-Heidelberg: Springer, 2013, p. 623-633Chapter in book (Refereed)
    Abstract [en]

    In this commemorative volume we honor Professor M. G. Velarde (MGV) on 4account of his remarkable achievements in the new and exciting domain of Complex Systems and Non-Linear Dynamics in general and the study of novel electric trans- 6port mechanisms in particular, for recent references see e.g. [1–3]. Our trajectories first crossed during a workshop, under the chairmanship of Profs. I. Prigogine and G. Nicolis, to discuss the European Commission’s working document on Prospects in the Science of Complexity in European Research within the Fourth Framework Programme in 1994. In these panel reports fundamental problems in complex systems research were laid down with particular emphasis on viewing phenomena from the microscopic scale to the macroscopic one including the emergence of selforganization in the information technology and the biology sectors.

  • 34.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theortical Chemistry.
    Examining the Limits of Physical Theory: Analytical Principles and Logical Implications2012In: Unstable States in the Continuous Spectra: Pt II: Interpretation, Theory and Applications, Elsevier, 2012, p. 33-117Chapter in book (Refereed)
    Abstract [en]

    Owing to the remarkable agreement between precise quantum chemical predictions and the most accurate experiments including sophisticated advanced instrumentation, it is usually concluded that the many-body Schrodinger equation in particular and also quantum mechanics in general describe reality to an unsurpassed exactitude. However, the correlation between the micro- and the macroscopic (classical) levels leads to well-known paradoxes in our fundamental scientific understanding. Hence, our aim is to examine the characteristics and the rationale for developing an analytic foundation for rigorous extensions of quantum mechanics beyond its long-established domain in physics, chemistry, and biology. In this discourse, we will see the fundamental importance of the notion of so-called unstable states, their definition, determination, and characterization. Within this vein, paradoxical and inconsistent issues related to the various attempts to apply microscopic organization to derive scientific laws in the macroworld are considered. The theoretical framework is augmented with quantum logical principles via a reformulation of Goders theorems. We arrange the assemblage of the mathematical ideas as follows. First, we give a detailed examination of the second-order differential equation with respect to specific boundary conditions and associated spectral expansions, followed by a general formulation via precise complex symmetric representations exemplified and derived from dilation analytic transformations. Associated dynamical timescales are represented and investigated via the corresponding Dunford formula. Relevant applications, where the above-mentioned unstable or metastable states emerge, are reviewed and compared with conventional bound-state and scattering theories with an analysis of their directive performance and stability. The manifestation and generation of triangular Jordan block entities as extended versions of nonstationary states are derived and further investigated and generalized to thermally excited scattering environments of open dissipative systems. Illustrative applications to condensed- and soft condensed matter are provided, and a surprising treatment is given to the Einstein laws of relativity. As a conclusion, we emphasize the computational and model building advantages of a conceptual continuation of quantum mechanics to rigorously incorporate universal complex resonance structures, their life times, and associated localization properties. We also prove the appearance of nonconventional time evolution including the emergence of Jordan blocks in the propagator, which leads to the origin of so-called coherent dissipative structures (CDSs) derived via uniquely defined spatiotemporal neumatic (from the Greek pneuma) units. This self-referential organization yields specific information bearing transformations, cf. the Godel encoding system, which might connect developmental and building matters with functional and mental issues within a biological framework at the same time providing background-dependent features of both special and general relativity theory. With these theoretical ideas as background, we advocate a new clarification of the dilemma facing micro macro correlates including an original characterization of unus mundus, i.e., the underlying holistic reality. Examining the Limits of Physical Theory: Analytical Principles and Logical Implications

  • 35.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Frontiers in Quantum Methods and Applications in Chemistry and Physics: Selected Proceedings of QSCP-XVIII (Paraty, Brazil, December, 2013)2015 (ed. A29)Book (Refereed)
    Abstract [en]

    This volume collects 15 selected papers from the scientific contributions presented at the Eighteenth International Workshop on Quantum Systems in Chemistry, Physics, and Biology (QSCP-XVIII), which was organized by Prof. M.A.C. Nascimento at the Casa da Cultura in Paraty (Rio de Janeiro), Brazil, from December 1 to 7, 2013. Over 100 scientists from 25 countries attended this meeting. Participants of the QSCP-XVIII workshop discussed the state of the art, new trends, and future evolution of methods in molecular quantum mechanics, and their applications to a wide variety of problems in chemistry, physics, and biology. The high-level attendance attained in this conference was particularly gratifying. It is the renowned interdisciplinary nature and friendly feeling of QSCP meetings that make them such successful discussion forums. Paraty is located in the south coast of Brazil, 250 km from Rio de Janeiro, the state capital. This historical town, nestled on the Costa Verde, is a living memory of the Gold Cycle: gold extracted from the mines of the state of Minas Gerais was transported by mule along the Estrada Real down to Paraty and from there shipped to Rio de Janeiro. The area of Paraty is probably the only place on the planet that brings together a native forest about 80 % preserved, a bay protected from the open sea by over a hundred islands, and a seventeenth-century town which is regarded by UNESCO as the most harmonious baroque location in the world. From this past originate the relics and traditions that so enchant the visitors: a wonderful wealth of cultural and ecological attractions, as well as a tourist infrastructure consisting of cosy inns and picturesque restaurants. Details of the Paraty meeting, including the scientific program, can be found on the web site: http://www.qscp2013.iq.ufrj.br. Altogether, there were 18 morning and afternoon sessions, where 55 plenary talks were given, and two evening poster sessions, with 18 fl ash presentations for a total of 38 displayed posters. We are grateful to all participants for making the QSCP-XVIII workshop a stimulating experience and a great success. QSCP-XVIII followed the traditions established at previous workshops:

     QSCP-I, organized by Roy McWeeny in 1996 at San Miniato (Pisa, Italy);

    QSCP-II, by Stephen Wilson in 1997 at Oxford (England);

    QSCP-III, by Alfonso Hernandez-Laguna in 1998 at Granada (Spain);

    QSCP-IV, by Jean Maruani in 1999 at Marly-le-Roi (Paris, France);

    QSCP-V, by Erkki Brä ndas in 2000 at Uppsala (Sweden);

    QSCP-VI, by Alia Tadjer in 2001 at Sofi a (Bulgaria);

    QSCP-VII, by Ivan Hubac in 2002 near Bratislava (Slovakia);

    QSCP-VIII, by Aristides Mavridis in 2003 at Spetses (Athens, Greece);

    QSCP-IX, by Jean-Pierre Julien in 2004 at Les Houches (Grenoble, France);

    QSCP-X, by Souad Lahmar in 2005 at Carthage (Tunisia);

    QSCP-XI, by Oleg Vasyutinskii in 2006 at Pushkin (St Petersburg, Russia);

    QSCP-XII, by Stephen Wilson in 2007 near Windsor (London, England);

    QSCP-XIII, by Piotr Piecuch in 2008 at East Lansing (Michigan, USA);

    QSCP-XIV, by Gerardo Delgado-Barrio in 2009 at El Escorial (Madrid, Spain);

    QSCP-XV, by Philip Hoggan in 2010 at Cambridge (England);

    QSCP-XVI, by Kiyoshi Nishikawa in 2011 at Kanazawa (Japan);

    QSCP-XVII, by Matti Hotokka in 2012 at Turku (Finland).

    The lectures presented at QSCP-XVIII were grouped into nine areas in the field of Quantum Systems in Chemistry, Physics, and Biology , ranging from Concepts and Methods in Quantum Chemistry and Physics through Molecular Structure and Dynamics, Reactive Collisions and Chemical Reactions, to Computational Chemistry, Physics, and Biology. The width and depth of the topics discussed at QSCP-XVIII are refl ected in the contents of this volume of proceedings in the book series Progress in Theoretical Chemistry and Physics, which includes four sections:

    I. Quantum Methodology (3 papers);

    II. Structure and Properties (4 papers);

    III. Molecular Dynamics (4 papers);

    IV. Fundamental Theory (3 papers).

    In addition to the scientifi c program, the workshop had its usual share of cultural events. There was a boat cruise in the Paraty bay and a show by the internationally known group Contador de Estórias . The award ceremony of the CMOA Prize and Medal took place during the congress banquet in the most traditional restaurant of Paraty, Margarida Café. The CMOA Prize was shared between two selected nominees: Jer-Lai Kuo and Yuan-Chung Cheng, both from Taiwan. Two other nominees, Jhih-Wei Chu (from Taiwan) and Andriy Loboda (from Ukraine) received a certifi cate of nomination and a gift. The prestigious CMOA Medal for senior scientists was awarded to Prof. Lorentz Cederbaum (University of Heidelberg, Germany). According to a custom of QSCP meetings, the venue of the next yearly workshop was announced to be in Odessa, Ukraine, in 2015, followed by one in Taipei, Taiwan, in 2016. However, due to the political events, the dates of the two meetings were later reversed. We are pleased to acknowledge the generous support given to the QSCP-XVIII conference by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), the City of Paraty Convention Bureau and Casa da Cultura  of Paraty. We are most grateful to all members of the Local Organizing Committee for their work and dedication, which made the stay and work of participants both pleasant and fruitful. We also thank the members of the International Scientifi c Committee and the Honorary Committee for their invaluable expertise and advice. We hope the readers will fi nd as much interest in consulting these proceedings as the participants in attending the meeting.

    M.A.C. Nascimento

    Jean Maruani

    Erkki J. Brändas

    Gerardo Delgado-Barrio

  • 36.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Non-hermitian quantum mechanics2012In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 112, no 15, p. 2764-2765Article, book review (Other academic)
  • 37.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Preface2015Book (Other academic)
    Abstract [en]

    PREFACE

     

    Advances in Quantum Chemistry provides researchers in quantum chemistry, physical chemistry and chemical physics with up-to-date surveys, invited reviews and highlights of recent achievements. Although the field of quantum chemistry has emerged as a subject of its own it overlaps fundamentally with other fields like applied mathematics, theoretical biology, signal processing including applications in medicine.

    In the present volume, the readers are presented with an exciting combination of themes, i.e. a description of anti-ferromagnetism in copper oxide, proton-conducting mechanism in solid oxide fuel cells, time-dependent processes in molecular processes, the essence of chemical bonding, biological models for repair of cellular radiation damage, momentum space methods for accurate molecular electronic structure calculations and functional theoretic models for hydrogen bonding networks and proton wires in water oxidation reactions.

     

    The first chapter in this volume Chapter, by Kimichika Fukushima, deals with the description of antiferromagaetism in copper oxides using density functional theory.  This is a longstanding problem, and the solution is discussed in terms of the variational method based SIWB (surrounding or solid Coulomb-potential-induced well for basis set) scheme.  The characteristics of the well stabilizing the O2- ion and making antiferromagaetism possible are discussed.

     

    In the second chapter Taku Onishi investigates proton-conducting mechanisms in solid electrolyte oxide fuel cells. Specifically LaAlO3 perovskite is allegedly proposed and compared with conventional perovskite-type conductors. The analysis, based on hybrid Kohn-Sham density functional theory, characterizing the proton conducting pathways, confronts mechanism elucidation and material design, including safety aspects regarding the conflicts with oxide ion conduction. In particular as the oxygen vacancy, doped to incorporate the proton, may conflict with oxide ion conduction, it was concluded, when utilizing LaAlO3 that the temperature strictly regulates the prevention of coincident oxide ion conduction.

     

    In Chapter 3, Yngve Öhrn presents and discusses a time dependent treatment of molecular processes.  The scheme, known as electron nuclear dynamics (END), is described in formal detail wich includes the choice of coordinate system and its effect on the molecular Hamiltonian, the choice of molecular wave function and the particular role of the time-dependent parameters that originates in a coherent state representation is discussed.  References are given to some of the work done with ENDYNE.

     

    Chapter 4 concerns chemical bonding. In the present contribution, Elena Sheka describes her experiences of chemical bonds in various investigations of structural chemistry. The investigations comprise a rich selection of chemical compounds from single, double and triple bonds, involving carbon, to provoking the main issues of modern chemistry devoted to fullerenes and recently graphene, the famous nobeliated 2D solid. The structures investigated permit a rather simple methodology based on the odd electron strategy, predominantly advocated by the author.

     

    In chapter 5, Dževad and Karen Belkić, advance their notable input to a far-reaching and across-the-board biophysical and chemical analysis of surviving fractions of irradiate cells and their new mechanistic repair-based Padé linear-quadratic model, PLQ. As current dose planning systems in radiotherapy, based on linear-quadratic models (LQ), is satisfactory only at low doses and inadequate for treatment modalities, or hyperfractionation, it is demonstrated that PLQ significantly outperforms LQ models regarding cell survival fractions including saturation effects.

     

    Although Gaussian technology has greatly simplified mainstream quantum chemistry, it is a cognizant fact that exponential-type orbitals, ETO’s, are better suited for molecular electronic structure calculations. In chapter 6, James and John Avery contribute to new progress in quantum chemistry by using Fock’s projection of 3D momentum space to 4D hyperspherical harmonics. The authors exploit their extraordinary competence in treating so-called Coulomb Sturmians to derive a general mathematical theorem including elegant, rapid and accurate evaluations of appropriate quantum mechanical molecular integrals. The ensuing closed form expression is illustrated by adequate examples.

     

    The final contribution to this volume, Chapter 7 by Yamaguchi et al., uses a QM/MM method to calculate complicated properties of water oxidation in the biosystem known as photosystem II (PSII).  Water oxidation in the oxygen evolving complex of PSII is dependent on the hydrogen-bonding networks.  The QM/MM computations elucidate the network structures: hydrogen–bonding O…. O(N) and O…H distances and O(N)-H…O angles in PRP, together with the Cl-O(N) and Cl…H distances and O(N)-H…Cl angles for chloride anions.  The results are compared with experiment.

     

    As advertised, the contents of this volume are multifarious as regards both fundamental theory and innovative applications. The contributing authors have made great strides to share their insights with the reader of the Advances. As series editors, we hope that the present volume will impart the same pleasure and enjoyment as we faced during the preparation of this volume.

     John R. Sabin and Erkki J. Brändas

  • 38.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Proposed Explanation of the Phi Phenomenon from a Basic Neural Viewpoint2015In: Quantum Biosystems, ISSN 1970-223X, Vol. 6, no 1, p. 160-171Article in journal (Refereed)
    Abstract [en]

    A first principle representation of integrated quantum thermal correlations of autaptic neurons associated with conscious brain mechanisms is proposed – the former termed the retinoid system by Trehub. Within this formulation, one descends on a set of unitary transformations yielding generic symmetries of the reduced neuronal dynamics illustrating the projection of the abstract degrees of freedom onto 3D space. The actual spatio-temporal symmetry suggests a general mirroring interpretation of the autapse as given by the structure of the neuronal network. The theory prompts a motif for the abundance of chemical synapses from a neuron onto itself and provides a simple explanation of the phi phenomenon and the Necker cube optical illusion.

  • 39.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Some Biochemical Reflections on Information and Communication2013In: Advances in Quantum Methods and Applications in Chemistry, Physics, and Biology, Heidelberg-New York: Springer Science+Business Media B.V., 2013, p. 75-98Conference paper (Refereed)
    Abstract [en]

    The biochemical aspects of communication have been investigated via anextended framework of original quantum-statistical concepts. The key idea developsfrom the notion of a so-called Spatio-Temporal Neumatic, STN, configuration,an open dissipative structure resting on the boundaries connecting micro-, meso- and macroscopic levels. In this category one finds de novo self-organization of molecular motion, enzymatic catalysis and the self-assembly of nano-structures all the way to biologically relevant processes like cell evolution, cellular neurobiology etc. The possibility to store and communicate coded messages in this enlarged organization is documented and recognized, unifying various proposals of theoretical understanding including in particular the law of Gödelian self-reference. It is demonstrated that intra-cell and inter-cell order leads to differentiation through a Poissonian modus operandi. The latter lacks intrinsic memory, but its statistical nature gives way to something non-intrinsic of teleonomic significance. Various consequences of this idea prompt a broadened notion of communication and information, generating encodable cell differentiation through cell quality value factors resonating through original communication channels accessible through Poisson statistics. It is shown that inter-cell communication is temporally dominated while intra-cell information is largely spatio-controlled. The nested (spatio-temporal) property of the “code of codes” extends from the genetic- through the socio-, ecological- and to the cosmological rank, while taking account of a more stringent and appraisable representation of the contemporary concept of a meme.

  • 40.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    There Are Quantum Jumps2015In: Mathematics, ISSN 2227-7390, Vol. 3, no 2, p. 319-328Article in journal (Refereed)
    Abstract [en]

    In this communication we take up the age-old problem of the possibility to incorporate quantum jumps. Unusually, we investigate quantum jumps in an extended quantum setting, but one of rigorous mathematical significance. The general background for this formulation originates in the Balslev-Combes theorem for dilatation analytic Hamiltonians and associated complex symmetric representations. The actual jump is mapped into a Jordan block of order two and a detailed derivation is discussed for the case of the emission of a photon by an atom. The result can be easily reassigned to analogous cases as well as generalized to Segrè characteristics of arbitrary order.

  • 41.
    Brändas, Erkki J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theortical Chemistry.
    Time Asymmetry and the Evolution of Physical Laws2012In: Advances in the Theory of Quantum Systems in Chemistry and Physics, 2012, p. 3-34Conference paper (Refereed)
    Abstract [en]

    In previous studies we have advocated a retarded-advanced sub-dynamics that goes beyond standard probabilistic formulations supplying a wide-range of interpretations. The dilemma of time reversible microscopic physical laws and the irreversible nature of thermodynamical equations are re-examined from this point of view. The subjective character of statistical mechanics, i.e. with respect to the theoretical formulation relative to a given level of description, is reconsidered as well. A complex symmetric ansatz, incorporating both time reversible and time irreversible evolutions charts the evolution of the basic laws of nature and reveals novel orders of organization. Examples are drawn from the self-organizational behaviour of complex biological systems as well as background dependent relativistic structures including Einstein's laws of relativity and the perihelion movement of Mercury. A possible solution to the above mentioned conundrum is provided for, as a consequence of a specific informity rule in combination with a Godelian like decoherence code protection. The theory comprises an interesting cosmological scenario in concert with the second law.

  • 42.
    Brändas, Erkki J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Lunell, Sten
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Obituary: Osvaldo Goscinski (1938–2013)2015Other (Other academic)
  • 43.
    Brändas, Erkki
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Szabados, Ágnes
    Eötvös Loránd University.
    Surján, Péter
    Eötvös Loránd University.
    Preface: Eighth Congress of the International Society for Theoretical ChemicalPhysics (ISTCP-VIII)2014In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 114, p. 959-960Article in journal (Refereed)
  • 44.
    Caldwell, Dennis
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Conundrums in Chemical Physics2013In: Advances in Quantum Chemistry, Elsevier, 2013, p. 31-111Chapter in book (Refereed)
    Abstract [en]

    In this review, we identify several fundamental concepts and models that have been challenging to students and teachers: (1) the Marcus theory of electron transfer reactions; (2) the Landau-Zener model for diabatic transitions; (3) the concept of reaction path curvature as illustrated by the affine transformation; and (4) a progression of stochastic models: the Langevin equation, the Fokker-Planck equation, and Kramers' theory of phase space diffusion as embodied in the Klein-Kramers equation. The gravamen of the work is the connection between Kramers' version of Transition State theory in the context of phase space diffusion. These classical concepts are then transferred to the realm of quantum chemistry, where we outline a program for tracking ensembles of time-dependent wave functions in analogy with their classical counterparts by means of a superoperator space and a Trace Algebra.

  • 45.
    Caldwell, Dennis
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Conundrums in Chemical Physics2013In: Advances in Quantum Chemistry, ISSN 0065-3276, E-ISSN 2162-8815, Vol. 66, p. 31-111Article in journal (Refereed)
    Abstract [en]

    In this review, we identify several fundamental concepts and models that have been challenging to students and teachers: (1) the Marcus theory of electron transfer reactions; (2) the Landau–Zener model for diabatic transitions; (3) the concept of reaction path curvature as illustrated by the affine transformation; and (4) a progression of stochastic models: the Langevin equation, the Fokker–Planck equation, and Kramers’ theory of phase space diffusion as embodied in the Klein–Kramers equation.

    The gravamen of the work is the connection between Kramers’ version of Transition State theory in the context of phase space diffusion. These classical concepts are then transferred to the realm of quantum chemistry, where we outline a program for tracking ensembles of time-dependent wave functions in analogy with their classical counterparts by means of a superoperator space and a Trace Algebra.

  • 46. Chaudret, Robin
    et al.
    Contreras-Garcia, Julia
    Delcey, Mickaël
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Parisel, Olivier
    Yang, Weitao
    Piquemal, Jean-Philip
    Revisiting H2O Nucleation around Au+ and Hg2+: The Peculiar "Pseudo-Soft" Character of the Gold Cation2014In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 10, no 5, p. 1900-1909Article in journal (Refereed)
    Abstract [en]

    In this contribution, we propose a deeper understanding of the electronic effects affecting the nucleation of water around the Au+ and Hg2+ metal cations using quantum chemistry. To do so, and in order to go beyond usual energetical studies, we make extensive use of state of the art quantum interpretative techniques combining ELF/NCI/QTAIM/EDA computations to capture all ranges of interactions stabilizing the well characterized microhydrated structures. The Electron Localization Function (ELF) topological analysis reveals the peculiar role of the Au+ outer-shell core electrons (subvalence) that appear already spatially preorganized once the addition of the first water molecule occurs. Thus, despite the addition of other water molecules, the electronic structure of Au(H2O)(+) appears frozen due to relativistic effects leading to a maximal acceptation of only two waters in gold's first hydration shell. As the values of the QTAIM (Quantum Theory of Atoms in Molecules) cations's charge is discussed, the Non Covalent Interactions (NCI) analysis showed that Au+ appears still able to interact through longer range van der Waals interaction with the third or fourth hydration shell water molecules. As these types of interaction are not characteristic of either a hard or soft metal cation, we introduced the concept of a "pseudo-soft" cation to define Au+ behavior. Then, extending the study, we performed the same computations replacing Au+ with Hg2+, an isoelectronic cation. If Hg2+ behaves like Au+ for small water clusters, a topological, geometrical, and energetical transition appears when the number of water molecules increases. Regarding the HSAB theory, this transition is characteristic of a shift of Hg2+ from a pseudosoft form to a soft ion and appears to be due to a competition between the relativistic and correlation effects. Indeed, if relativistic effects are predominant, then mercury will behave like gold and have a similar subvalence/geometry; otherwise when correlation effects are predominant, Hg2+ behaves like a soft cation.

  • 47. Chen, Shufeng
    et al.
    Navizet, Isabelle
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Liu, Yajun
    Ferre, Nicolas
    Hybrid QM/MM Simulations of the Obelin Bioluminescence and Fluorescence Reveal an Unexpected Light Emitter2014In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 118, no 11, p. 2896-2903Article in journal (Refereed)
    Abstract [en]

    Obelia longissima, a tiny hydrozoan living in temperate and cold seas, features the Obelin photoprotein, which emits blue light. The Obelin bioluminescence and the Ca2+-discharged Obelin fluorescence spectra show multimodal characteristics that are currently interpreted by the concomitant participation of several light emitters. Up to now, the coelenteramide luminophore is thought to exist in different protonation states, one of them engaged in an ion-pair with the nearby residue, His22. Using hybrid quantum mechanics/molecular mechanics (QM/MM) calculations, we demonstrate that such an ion-pair cannot exist as a stable light emitter. However, when His22 electric neutrality is maintained by means of another proton transfer, the phenolate state of coelenteramide exhibits emission properties in agreement with experiment. Finally, an alternative nonradiative decay pathway, involving the formation of a diradical excited state, is postulated for the first time.

  • 48. Chen, Shu-Feng
    et al.
    Navizet, Isabelle
    Roca-Sanjuán, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Liu, Ya-Jun
    Ferre, Nicolas
    Chemiluminescence of Coelenterazine and Fluorescence of Coelenteramide: A Systematic Theoretical Study2012In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 8, no 8, p. 2796-2807Article in journal (Refereed)
    Abstract [en]

    A systematic investigation of the structural and spectroscopic properties of coelenteramide has been performed at the TD-CAM-B3LYP/6-31+G(d,p) level of theory, including various fluorescence and chemiluminescence states. The influence of geometric conformations, solvent polarity, protonation state, and the covalent character of the O-H bond of the hydroxyphenyl moiety were carefully studied. Striking differences in geometries and electronic structures among the states responsible for light emission were characterized. All fluorescence states can be described as a limited charge transfer process for a planar amide moiety. However, the chemiluminescence state is characterized by a much larger charge transfer that takes place over a longer distance. Moreover, the chemiluminescent coelenteramide structure exhibits an amide moiety that is no longer planar, in agreement with recent, more accurate ab initio results [Roca-Sanjuan et al J. Chem. Theory Comput. 2011, 7, 4060] Because the chemiluminescence state appears to be completely dark, a new mechanism is tentatively introduced for this process.

  • 49. Corchado, José C.
    et al.
    Sánchez, M. Luz
    Fernández Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Martín, M. Elena
    Muñoz-Losa, Aurora
    Barata-Morgado, Rute
    Aguilar, Manuel A.
    Theoretical Study of Solvent Effects on the Ground and Low-Lying Excited Free Energy Surfaces of a Push–Pull Substituted Azobenzene2014In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 118, no 43, p. 12518-12530Article in journal (Refereed)
    Abstract [en]

    The ground and low-lying excited free energy surfaces of 4-amino-4'-cyano azobenzene, a molecule that has been proposed as building block for chiroptical switches, are studied in gas phase and a variety of solvents (benzene, chloroform, acetone, and water). Solvent effects on the absorption and emission spectra and on the cistrans thermal and photo isomerizations are analyzed using two levels of calculation: TD-DFT and CASPT2/CASSCF. The solvent effects are introduced using a polarizable continuum model and a QM/MM method, which permits one to highlight the role played by specific interactions. We found that, in gas phase and in agreement with the results found for other azobenzenes, the thermal cistrans isomerization follows a rotation-assisted inversion mechanism where the inversion angle must reach values close to 180 degrees but where the rotation angle can take almost any value. On the contrary, in polar solvents the mechanism is controlled by the rotation of the CN=NC angle. The change in the mechanism is mainly related to a better solvation of the nitrogen atoms of the azo group in the rotational transition state. The photoisomerization follows a rotational pathway both in gas phase and in polar and nonpolar solvents. The solvent introduces only small modifications in the n pi* free energy surface (S-1), but it has a larger effect on the pi pi* surface (S-2) that, in polar solvents, gets closer to S-1. In fact, the S-2 band of the absorption spectrum is red-shifted 0.27 eV for the trans isomer and 0.17 eV for the cis. In the emission spectrum the trend is similar: only S-2 is appreciably affected by the solvent, but in this case a blue shift is found.

  • 50. Daku, Latevi Max Lawson
    et al.
    Aquilante, Francesco
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Robinson, Timothy W.
    Hauser, Andreas
    Accurate Spin-State Energetics of Transition Metal Complexes. 1. CCSD(T), CASPT2, and DFT Study of [M(NCH)(6)](2+) (M = Fe, Co)2012In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 8, no 11, p. 4216-4231Article in journal (Refereed)
    Abstract [en]

    Highly accurate estimates of the high-spin/low-spin energy, difference Delta E-HL(el) in the high-spin complexes [Fe(NCH)(6)](2+) and [Co(NCH)(6)](2+) have been obtained from the results of CCSD(T) calculations extrapolated to the complete basis set limit. These estimates are shown to be strongly influenced by scalar relativistic effects. They have been used to assess the performances of the CASPT2 method and 30 density functionals of the GGA, meta-GGA, global hybrid, RSH, and double-hybrid types. For the CASPT2 method, the results of the assessment support the proposal [Kepenekian, M.; Robert, V.; Le Guennic, B. J. Chem. Phys. 2009, 131, 114702] that the ionization potential-electron affinity (IPEA) shift defining the zeroth-order Hamiltonian be raised from its standard value of 0.25 au to 0.50-0.70 au for the determination of Delta E-HL(el) in Fe(II) complexes with a [FeN6] core. At the DFT level, some of the assessed functionals proved to perform within chemical accuracy (+/- 350 cm(-1)) for the spin-state energetics of [Fe(NCH)(6)](2+), others for that of [Co(NCH)(6)](2+), but none of them simultaneously for both complexes. As demonstrated through a reparametrization of the CAM-PBEO range-separated hybrid, which led to a functional that performs within chemical accuracy for the spin-state energetics of both complexes, performing density functionals of broad applicability may be devised by including in their training sets highly accurate data like those reported here for [Fe(NCH)(6)](2+) and [Co(NCH)(6)](2+).

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