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Fernández Galván, IgnacioORCID iD iconorcid.org/0000-0002-0684-7689
Alternative names
Publications (10 of 31) Show all publications
Schalk, O., Galiana, J., Geng, T., Larsson, T., Thomas, R., Fernández Galván, I., . . . Vacher, M. (2020). Competition between ring-puckering and ring-opening excited state reactions exemplified on 5H-furan-2-one and derivatives. Journal of Chemical Physics, 152(6), Article ID 064301.
Open this publication in new window or tab >>Competition between ring-puckering and ring-opening excited state reactions exemplified on 5H-furan-2-one and derivatives
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2020 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 152, no 6, article id 064301Article in journal (Refereed) Published
Abstract [en]

The influence of ring-puckering on the light-induced ring-opening dynamics of heterocyclic compounds was studied on the sample 5-membered ring molecules γ-valerolactone and 5H-furan-2-one using time-resolved photoelectron spectroscopy and ab initio molecular dynamics simulations. In γ-valerolactone, ring-puckering is not a viable relaxation channel and the only available reaction pathway is ring-opening, which occurs within one vibrational period along the C—O bond. In 5H-furan-2-one, the C=C double bond in the ring allows for ring-puckering which slows down the ring-opening process by about 150 fs while only marginally reducing its quantum yield. This demonstrates that ring-puckering is an ultrafast process, which is directly accessible upon excitation and which spreads the excited state wave packet quickly enough to influence even the outcome of an otherwise expectedly direct ring-opening reaction.

National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-404396 (URN)10.1063/1.5129366 (DOI)000522040400014 ()32061211 (PubMedID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg FoundationWenner-Gren FoundationsSwedish National Infrastructure for Computing (SNIC)
Available from: 2020-02-19 Created: 2020-02-19 Last updated: 2020-05-06Bibliographically approved
Sankari, A., Stråhlman, C., Sankari, R., Partanen, L., Laksman, J., Kettunen, J. A., . . . Sorensen, S. L. (2020). Non-radiative decay and fragmentation in water molecules after 1a1-14a1 excitation and core ionization studied by electron-energy-resolved electron–ion coincidence spectroscopy. Journal of Chemical Physics, 152(7), Article ID 074302.
Open this publication in new window or tab >>Non-radiative decay and fragmentation in water molecules after 1a1-14a1 excitation and core ionization studied by electron-energy-resolved electron–ion coincidence spectroscopy
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2020 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 152, no 7, article id 074302Article in journal (Refereed) Published
Abstract [en]

In this paper, we examine decay and fragmentation of core-excited and core-ionized water molecules combining quantum chemical calculations and electron-energy-resolved electron–ion coincidence spectroscopy. The experimental technique allows us to connect electronic decay from core-excited states, electronic transitions between ionic states, and dissociation of the molecular ion. To this end, we calculate the minimum energy dissociation path of the core-excited molecule and the potential energy surfaces of the molecular ion. Our measurements highlight the role of ultra-fast nuclear motion in the 1a1-14a1 core-excited molecule in the production of fragment ions. OH+ fragments dominate for spectator Auger decay. Complete atomization after sequential fragmentation is also evident through detection of slow H+ fragments. Additional measurements of the non-resonant Auger decay of the core-ionized molecule (1a1-1) to the lower-energy dication states show that the formation of the OH+ + H+ ion pair dominates, whereas sequential fragmentation OH+ + H+ → O + H+ + H+ is observed for transitions to higher dication states, supporting previous theoretical investigations.

National Category
Theoretical Chemistry Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-404397 (URN)10.1063/1.5141414 (DOI)000519820800001 ()32087651 (PubMedID)
Funder
Swedish Research CouncilAcademy of Finland
Available from: 2020-02-19 Created: 2020-02-19 Last updated: 2020-04-22Bibliographically approved
Fernández Galván, I., Gustafsson, H. & Vacher, M. (2019). Chemiexcitation without the Peroxide Bond?: Replacing oxygen with other heteroatoms. ChemPhotoChem, 3(9), 957-967
Open this publication in new window or tab >>Chemiexcitation without the Peroxide Bond?: Replacing oxygen with other heteroatoms
2019 (English)In: ChemPhotoChem, ISSN 2367-0932, Vol. 3, no 9, p. 957-967Article in journal (Refereed) Published
Abstract [en]

Chemiexcitation is the population of electronic excited states from the electronic ground state via radiationless non-adiabatic transitions upon thermal activation. The subsequent emission of the excess of energy in the form of light is called chemiluminescence or bioluminescence when occurring in living organisms. Key intermediates in these reactions have been shown to contain a high-energy (often cyclic) peroxide which decomposes. The simplest molecules, 1,2-dioxetane and 1,2-dioxetanone, have thus been used extensively both theoretically and experimentally as model systems to understand the underlying mechanisms of chemiexcitation. An outstanding question remains whether the peroxide bond is a necessity and whether equivalent processes could happen in other simple molecules not containing an OO bond. In the present work, the decomposition reactions of four analogs of 1,2-dioxetane not containing a peroxide bond, the 1,2-oxazetidine anion, the 1,2-diazetidine anion, (neutral) 1,2-oxazetidine and 1,2-dithietane, have been studied theoretically using ab initio multicongurational methods. In particular, the reaction energy barriers and spin-orbit coupling strengths were calculated; the electronic degeneracy was studied and compared to the case of 1,2-dioxetane to assess the potentiality of chemiexcitation in the analog molecules.

Keywords
chemiexcitation, chemiluminescence, 1.2-dioxetane, ab initio calculations, computational photochemistry
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-372040 (URN)10.1002/cptc.201800232 (DOI)000487014600032 ()
Funder
Swedish Research Council, 2016-03398Swedish National Infrastructure for Computing (SNIC)
Available from: 2019-01-04 Created: 2019-01-04 Last updated: 2019-10-31Bibliographically approved
Häse, F., Fernández Galván, I., Aspuru-Guzik, A., Lindh, R. & Vacher, M. (2019). How machine learning can assist the interpretation of ab initio molecular dynamics simulations and conceptual understanding of chemistry. Chemical Science, 10(8), 2298-2307
Open this publication in new window or tab >>How machine learning can assist the interpretation of ab initio molecular dynamics simulations and conceptual understanding of chemistry
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2019 (English)In: Chemical Science, ISSN 2041-6520, Vol. 10, no 8, p. 2298-2307Article in journal (Refereed) Published
Abstract [en]

Molecular dynamics simulations are often key to the understanding of the mechanism, rate and yield of chemical reactions. One current challenge is the in-depth analysis of the large amount of data produced by the simulations, in order to produce valuable insight and general trends. In the present study, we propose to employ recent machine learning analysis tools to extract relevant information from simulation data without a priori knowledge on chemical reactions. This is demonstrated by training machine learning models to predict directly a specific outcome quantity of ab initio molecular dynamics simulations - the timescale of the decomposition of 1,2-dioxetane. The machine learning models accurately reproduce the dissociation time of the compound. Keeping the aim of gaining physical insight, it is demonstrated that, in order to make accurate predictions, the models evidence empirical rules that are, today, part of the common chemical knowledge. This opens the way for conceptual breakthroughs in chemistry where machine analysis would provide a source of inspiration to humans.

Place, publisher, year, edition, pages
The Royal Society of Chemistry, 2019
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-372043 (URN)10.1039/C8SC04516J (DOI)000459331200004 ()
Funder
Swedish Research Council, 2016-03398
Available from: 2019-01-04 Created: 2019-01-04 Last updated: 2019-08-01Bibliographically approved
Fernández Galván, I., Vacher, M., Alavi, A., Angeli, C., Aquilante, F., Autschbach, J., . . . Lindh, R. (2019). OpenMolcas: From Source Code to Insight. Journal of Chemical Theory and Computation, 15(11), 5925-5964
Open this publication in new window or tab >>OpenMolcas: From Source Code to Insight
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2019 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 15, no 11, p. 5925-5964Article in journal (Refereed) Published
Abstract [en]

In this Article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multiconfigurational wave function and density functional theory models. Some of these implementations include an array of additional options and functionalities. The paper proceeds and describes developments related to explorations of potential energy surfaces. Here we present methods for the optimization of conical intersections, the simulation of adiabatic and nonadiabatic molecular dynamics, and interfaces to tools for semiclassical and quantum mechanical nuclear dynamics. Furthermore, the Article describes features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism, and properties. Finally, the paper describes a number of built-in and add-on features to support the OpenMolcas platform with postcalculation analysis and visualization, a multiscale simulation option using frozen-density embedding theory, and new electronic and muonic basis sets.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-398580 (URN)10.1021/acs.jctc.9b00532 (DOI)000497260300014 ()31509407 (PubMedID)
Funder
Knut and Alice Wallenberg Foundation, KAW-2013.0020Swedish Research Council, 2012-3924Swedish Research Council, 2016-03398Swedish Research Council, VR 2015-03956EU, Horizon 2020, 658173EU, European Research CouncilStiftelsen Olle Engkvist ByggmästareNIH (National Institute of Health), GM126627 01German Research Foundation (DFG), BO 4915/1-1
Available from: 2019-12-09 Created: 2019-12-09 Last updated: 2019-12-09Bibliographically approved
Khamesian, M., Fernández Galván, I., Delcey, M. G., Sørensen, L. K. & Lindh, R. (2019). Spectroscopy of linear and circular polarized ligth with the exact semiclassical light–matter interaction. In: David A. Dixon (Ed.), Annual Reports in Computational Chemistry: Volume 15: (pp. 39-76). Elsevier
Open this publication in new window or tab >>Spectroscopy of linear and circular polarized ligth with the exact semiclassical light–matter interaction
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2019 (English)In: Annual Reports in Computational Chemistry: Volume 15 / [ed] David A. Dixon, Elsevier, 2019, p. 39-76Chapter in book (Refereed)
Abstract [en]

We present the theory and the analytical and numerical solution for the calculation of the oscillator and rotatory strengths of molecular systems using a state-specific formalism. For a start, this is done in the context of the exact semiclassical light–matter interaction in association with electronic wave functions expanded in a Gaussian basis. The reader is guided through the standard approximations of the field, e.g., the use of commutators, truncation of Taylor expansions, and the implications of these are discussed in parallel. Expressions for the isotropically averaged values are derived, recovering the isotropic oscillator strength in terms of the transition electric-dipole moment, and the isotropic rotatory strength in terms of the transition electric-dipole and magnetic-dipole moments. This chapter gives a detailed description of the computation of the integrals over the plane wave in association with Gaussian one-particle basis sets. Finally, a brief description is given of how the computed oscillator and rotatory strengths are related to the quantities commonly used and discussed in experimental studies.

Place, publisher, year, edition, pages
Elsevier, 2019
Series
Annual Reports in Computational Chemistry ; 15
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-398676 (URN)10.1016/bs.arcc.2019.08.004 (DOI)978-0-12-817119-6 (ISBN)
Available from: 2019-12-09 Created: 2019-12-09 Last updated: 2019-12-16Bibliographically approved
Vacher, M., Fernández Galván, I., Ding, B.-W., Schramm, S., Berraud-Pache, R., Naumov, P., . . . Lindh, R. (2018). Chemi- and Bioluminescence of Cyclic Peroxides. Chemical Reviews, 118(15), 6927-6974
Open this publication in new window or tab >>Chemi- and Bioluminescence of Cyclic Peroxides
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2018 (English)In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 118, no 15, p. 6927-6974Article, review/survey (Refereed) Published
Abstract [en]

Bioluminescence is a phenomenon that has fascinated mankind for centuries. Today the phenomenon and its sibling, chemiluminescence, have impacted society with a number of useful applications in fields like analytical chemistry and medicine, just to mention two. In this review, a molecular-orbital perspective is adopted to explain the chemistry behind chemiexcitation in both chemi- and bioluminescence. First, the uncatalyzed thermal dissociation of 1,2-dioxetane is presented and analyzed to explain, for example, the preference for triplet excited product states and increased yield with larger nonreactive substituents. The catalyzed fragmentation reaction and related details are then exemplified with substituted 1,2-dioxetanone species. In particular, the preference for singlet excited product states in that case is explained. The review also examines the diversity of specific solutions both in Nature and in artificial systems and the difficulties in identifying the emitting species and unraveling the color modulation process. The related subject of excited-state chemistry without light absorption is finally discussed. The content of this review should be an inspiration to human design of new molecular systems expressing unique light-emitting properties. An appendix describing the state-of-the-art experimental and theoretical methods used to study the phenomena serves as a complement.

National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-357512 (URN)10.1021/acs.chemrev.7b00649 (DOI)000441475900002 ()29493234 (PubMedID)
Funder
Swedish Research Council, 2016-03398Wenner-Gren Foundations
Note

PMID: 29493234

Available from: 2018-08-16 Created: 2018-08-16 Last updated: 2018-11-12Bibliographically approved
Fernández Galván, I. & Ugandi, M. (2018). Uncontracted basis sets for ab initio calculations of muonic atoms and molecules. International Journal of Quantum Chemistry, 118(21), Article ID e25755.
Open this publication in new window or tab >>Uncontracted basis sets for ab initio calculations of muonic atoms and molecules
2018 (English)In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, E-ISSN 1097-461X, Vol. 118, no 21, article id e25755Article in journal (Refereed) Published
Abstract [en]

n this work, we investigated muonic atoms and molecules from a quantum chemist's viewpoint by incorporating muons in the CASSCF model. With the aim of predicting muonic X‐ray energies, primitive muonic basis sets were developed for a selection of elements. The basis sets were then used in CASSCF calculations of various atoms and molecules to calculate muonic excited states. We described the influence of nuclear charge distribution in predicting muonic X‐ray energies. Effects of the electronic wave function on the muonic X‐ray energies were also examined. We have computationally demonstrated how the muon can act as a probe for the nuclear charge distribution or electronic wave function by considering lower or higher muonic excited states, respectively.

National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-369734 (URN)10.1002/qua.25755 (DOI)
Funder
Swedish Research Council, 2016‐03398
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2019-02-20Bibliographically approved
Farahani, P., Oliveira, M. A., Fernández Galván, I. & Baader, W. J. (2017). A combined theoretical and experimental study on the mechanism of spiro-adamantyl-1,2-dioxetanone decomposition. RSC Advances, 7(28), 17462-17472
Open this publication in new window or tab >>A combined theoretical and experimental study on the mechanism of spiro-adamantyl-1,2-dioxetanone decomposition
2017 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 28, p. 17462-17472Article in journal (Refereed) Published
Abstract [en]

1, 2-Dioxetanones have been considered as model compounds for bioluminescence processes. The unimolecular decomposition of these prototypes leads mainly to the formation of triplet excited states whereas in the catalysed decomposition of these peroxides singlet states are formed preferentially. Notwithstanding, these cyclic peroxides are important models to understand the general principles of chemiexcitation as they can be synthesised, purified and characterised. We report here results of experimental and theoretical approaches to investigating the decomposition mechanism of spiro-adamantyl- 1,2-dioxetanone. The activation parameters in the unimolecular decomposition of this derivative have been determined by isothermal kinetic measurements (30-70 degrees C) and the chemiluminescence activation energy calculated from the correlation of emission intensities. The activation energy for peroxide decomposition proved to be considerably lower than the chemiluminescence activation energy indicating the existence of different reaction pathways for ground and excited state formation. These experimental results are compared with the calculations at the complete active space second-order perturbation theory (CASPT2), which reveal a two-step biradical mechanism starting by weak peroxide bond breakage followed by carbon-carbon elongation. The theoretical findings also indicate different transition state energies on the excited and ground state surfaces during the C-C bond cleavage in agreement with the experimental activation parameters.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-322001 (URN)10.1039/c6ra26575h (DOI)000398802000063 ()
Available from: 2017-05-15 Created: 2017-05-15 Last updated: 2017-12-18
Vacher, M., Brakestad, A., Karlsson, H. O., Fernández Galván, I. & Lindh, R. (2017). Dynamical Insights into the Decomposition of 1,2-Dioxetane. Journal of Chemical Theory and Computation, 13(6), 2448-2457
Open this publication in new window or tab >>Dynamical Insights into the Decomposition of 1,2-Dioxetane
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2017 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 13, no 6, p. 2448-2457Article in journal (Refereed) Published
Abstract [en]

Chemiluminescence in 1,2-dioxetane occurs through a thermally activated decomposition reaction into two formaldehyde molecules. Both ground-state and nonadiabatic dynamics (including singlet excited states) of the decomposition reaction have been simulated, starting from the first O–O bond-breaking transition structure. The ground-state dissociation occurs between t = 30 fs and t = 140 fs. The so-called entropic trap leads to frustrated dissociations, postponing the decomposition reaction. Specific geometrical conditions are necessary for the trajectories to escape from the entropic trap and for dissociation to be possible. The singlet excited states participate as well in the trapping of the molecule: dissociation including the nonadiabatic transitions to singlet excited states now occurs from t = 30 fs to t = 250 fs and later. Specific regions of the seam of the So/S1 conical intersections that would "retain" the molecule for longer on the excited state have been identified.

National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-329717 (URN)10.1021/acs.jctc.7b00198 (DOI)000403530100009 ()28437611 (PubMedID)
Funder
Swedish Research Council, 2012-3910
Available from: 2017-10-02 Created: 2017-10-02 Last updated: 2017-10-02Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-0684-7689

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