uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Towards an accurate molecular orbital theory for excited states: Ethene, butadiene, and hexatriene
Department of Theoretical Chemistry, Lund University.ORCID iD: 0000-0001-7567-8295
Show others and affiliations
1993 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 98, no 4, 3151-3162 p.Article in journal (Refereed) Published
Abstract [en]

A newly proposed quantum chemical approach for ab initio calculations of electronic spectra of molecular systems is applied to the molecules ethene, trans-1,3-butadiene, and trans-trans-1,3,5-hexatriene. The method has the aim of being accurate to better than 0.5 eV for excitation energies and is expected to provide structural and physical data for the excited states with good reliability. The approach is based on the complete active space (CAS) SCF method, which gives a proper description of the major features in the electronic structure of the excited state, independent of its complexity, accounts for all near degeneracy effects, and includes full orbital relaxation. Remaining dynamic electron correlation effects are in a subsequent step added using second order perturbation theory with the CASSCF wave function as the reference state. The approach is here tested in a calculation of the valence and Rydberg excited singlet and triplet states of the title molecules, using extended atomic natural orbital (ANO) basis sets. The ethene calculations comprised the two valence states plus all singlet and triplet Rydberg states of 3s, 3p, and 3d character, with errors in computed excitation energies smaller than 0.13 eV in all cases except the V state, for which the vertical excitation energy was about 0.4 eV too large. The two lowest triplet states and nine singlet states were studied in butadiene. The largest error (0.37 eV) was found for the 2 B-1(u) state. The two lowest triplet and seven lowest singlet states in hexatriene had excitation energies in error with less than 0.17 eV.

Place, publisher, year, edition, pages
1993. Vol. 98, no 4, 3151-3162 p.
National Category
Chemical Sciences
URN: urn:nbn:se:uu:diva-143946DOI: 10.1063/1.465071ISI: A1993KP93800064OAI: oai:DiVA.org:uu-143946DiVA: diva2:394320
Available from: 2011-02-02 Created: 2011-01-25 Last updated: 2015-01-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Lindh, Roland
In the same journal
Journal of Chemical Physics
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 427 hits
ReferencesLink to record
Permanent link

Direct link