Random-phase approximation correlation methods including exchange interactions
Dr. A. Hesselmann, Universität Erlangen-Nürnberg, Allemagne
Lundi 11 juin à 11 h, bibliothèque LCT, tour 12-13, 4e étage
It is known that the (direct) RPA method considerably overestimates
electron correlation energies of molecules due to the neglect
of higher order exchange contributions. Therefore, in order to correct
this self-correlation error of RPA, exchange terms have to be
accounted for. Unfortunately there is no unique way to
do this and so, in this talk, a number of different approaches will
be presented to improve the RPA method by adding exchange
contributions in various ways. It will be shown that some of these
approaches considerably improve on direct RPA for a number of properties
if a Kohn-Sham reference determinant is used. In contrast to this,
if the RPA method is based on a Hartree-Fock reference determinant,
clear improvements for reaction energies and intermolecular interactions
are observed if particle-particle and hole-hole interactions are
included that commonly are missing in standard RPA methods.