Optimized correlations: A practical pair density functional approach

Description

Density functional theory (DFT) is the most used tool for electronic structure calculations. In DFT all the many body physics is contained in the exchange correlation energy, which is a functional of the density. Instead, Burke et al. [1] wrote the exchange correlation energy as integral of the on top exchange correlation hole, which derives from the pair distribution function. Thus finding a good approximation for the pair distribution function is crucial for the performance of DFT. The most simplest approximation is the local density approximation (LDA). It approximates the on top exchange correlation hole at a certain point by that of the HEG, with the density equal to the density of the system at that point. We propose to use a Jastrow correlated wave function, optimized for the system of interest, to obtain the pair distribution function. In my contribution I estimate the numerical cost and performance for an implementation in 3D in a plain wave basis. Results for the pair distribution function in a 1D model system, with a periodically modulated density are shown[2]. The transition from a "LDA" regime to a "mean density approximation" regime is demonstrated, which is in accordance with findings of Gunnarson et al.[3]. [1] K. Burke et al., Journal of Chemical Physics, 109, 3760-3771 (1998) [2] M. Panholzer, Journal of Low Temperature Physics, 187, 639-645 (2017) [3] O. Gunnarsson et al., PRB, 20, 3136-3164, (1979)

Period	04 Apr 2018
Event title	From Electrons to Phase Transitions 2018, A ViCoM Conference
Event type	Conference
Location	AustriaShow on map