Time-dependent density-functional theory calculations of triplet-triplet absorption
2005 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 122, no 22Article in journal (Refereed) Published
We present density-functional theory calculations of triplet-triplet absorption by three different approaches based on time-dependent density-functional theory (DFT): unrestricted DFT linear response, open-shell restricted DFT linear response applied to the triplet state, and quadratic response with triplet excitations applied to the ground state. Comparison is also made with corresponding results obtained by Hartree-Fock and multiconfiguration self-consistent-field response theory. Two main conclusions concerning triplet-triplet transitions are drawn in this study: First, the very good agreement between unrestricted and restricted DFT results indicates that spin contamination of the triplet state is not a serious problem when computing triplet-triplet spectra of common organic molecules. Second, DFT response calculations of triplet-triplet transitions can be affected by triplet instability problems, especially for the combination of DFT quadratic response with functionals containing fractional exact Hartree-Fock exchange.
Place, publisher, year, edition, pages
2005. Vol. 122, no 22
gaussian-basis sets, correlated molecular calculations, ultra-violet photodissociation, potential-energy surfaces, open-shell molecules, excitation-energies, response functions, excited-states, ozone, approximation
IdentifiersURN: urn:nbn:se:kth:diva-14838DOI: 10.1063/1.1914772ISI: 000229858500006ScopusID: 2-s2.0-20744438212OAI: oai:DiVA.org:kth-14838DiVA: diva2:332879
QC 201005252010-08-052010-08-05Bibliographically approved