First principle calculations of dipole-dipole dispersion coefficients for the ground and first π → π∗ excited states of some azabenzenes
2004 (English)In: Journal of Computational Methods in Sciences and Engineering, ISSN 1472-7978, E-ISSN 1875-8983, Vol. 4, no 3, 321-332 p.Article in journal (Refereed) Published
The complex polarization propagator method has been applied to the calculation of dipole-dipole dispersion coefficients (also known as C6 coefficients) of pyridine, pyrazine, and s-tetrazine. These calculations refer to the electronic ground states as well as the first excited states of π → π∗ character. It is argued that accurate ground state dispersion coefficients are obtained with density functional theory using the B3LYP exchange-correlation functional. The proposed values for the C6 coefficients of pyridine, pyrazine, and s-tetrazine in their ground states are 1543 a.u., 1398 a.u., and 1014 a.u., respectively. Multi-configurational complete active space calculations are performed on these compounds in their respective π → π∗ excited state. The isotropic averages of the frequency-dependent polarizabilities are smaller in the excited states, but the effective frequencies-defined in the London-van der Waals dispersion relation-are on the other hand larger.
Place, publisher, year, edition, pages
IOS Press, 2004. Vol. 4, no 3, 321-332 p.
Density functional theory, Dispersions, Ground state, Pyridine, Van der Waals forces, Complete active space, Complex polarization propagator, Dispersion coefficient, Dispersion relations, Electronic ground state, Exchange-correlation functionals, First principle calculations, Frequency-dependent polarizabilities, Excited states
IdentifiersURN: urn:nbn:se:kth:diva-198799ScopusID: 2-s2.0-26044476395OAI: oai:DiVA.org:kth-198799DiVA: diva2:1058927
QC 201612222016-12-212016-12-212016-12-22Bibliographically approved