Exchange-Correlation Energy Densities and Response Potentials: Connection Between Two Definitions and Analytical Model for the Strong-Coupling Limit of a Stretched Bond
S. Giarrusso
Paola Gori-Giorgi
10.26434/chemrxiv.10283678.v1
https://chemrxiv.org/articles/preprint/Exchange-Correlation_Energy_Densities_and_Response_Potentials_Connection_Between_Two_Definitions_and_Analytical_Model_for_the_Strong-Coupling_Limit_of_a_Stretched_Bond/10283678
We analyze in depth two widely used definitions (from the theory of conditional probablity amplitudes and from the adiabatic connection formalism) of the exchange-correlation energy density and of the response potential of Kohn-Sham density functional theory. We introduce a local form of the coupling-constant-dependent Hohenberg-Kohn functional, showing that the difference between the two definitions is due to a corresponding local first-order term in the coupling constant, which disappears globally (when integrated over all space), but not locally. We also design an analytic representation for the response potential in the strong-coupling limit of density functional theory for a model single stretched bond.<br>
2019-11-20 11:49:22
density functional theory
exchange-correlation functionals