Quantum chemical comparison of vertical, adiabatic, and 0-0 excitation energies: The PYP and GFP chromophores
2012 (English)In: Journal of Computational Chemistry, ISSN 0192-8651, E-ISSN 1096-987X, Vol. 33, no 23, 1892-1901 p.Article in journal (Refereed) Published
A number of benchmark studies investigating the performance of quantum chemical methods for calculating vertical excitation energies are today available in the literature. However, less established is the variation between methods in their estimates of the differences between vertical, adiabatic, and 0-0 excitation energies. To this end, such excitation energies are here calculated for the bright S1 states of the anionic chromophores of the photoactive yellow protein (PYP) and the green fluorescent protein (GFP) in the gas phase using configuration interaction singles, complete active space self-consistent field, coupled-cluster singles and doubles, and time-dependent density functional theory methods. Although the estimates of the excitation energies vary by more than 1 eV between the methods, the differences between the different types of excitation energies are found to be relatively method-insensitive, varying by ∼0.1 eV only for these particular chromophores. Specifically, the adiabatic energies are uniformly 0.10–0.17 (PYP) and 0.06–0.17 eV (GFP) lower than the vertical energies, and the 0-0 energies are similarly 0.09–0.14 (PYP) and 0.07–0.17 eV (GFP) lower than the adiabatic energies.
Place, publisher, year, edition, pages
Wiley-Blackwell, 2012. Vol. 33, no 23, 1892-1901 p.
excited states, adiabatic excitation energies, ab initio methods, TD-DFT methods
IdentifiersURN: urn:nbn:se:liu:diva-79452DOI: 10.1002/jcc.23027ISI: 000306357800006OAI: oai:DiVA.org:liu-79452DiVA: diva2:542275
funding agencies|Linkoping University||Swedish Research Council||Carl Trygger Foundation||Olle Engkvist Foundation||UPPMAX||NSC||2012-07-312012-07-312013-03-07