A Proposal of the Approximate Kinetic Energy Functional of the Pair Density Functional Theory

Abstract

We propose the approximate kinetic energy (KE) functional of the pair density (PD) functional theory on the basis of the coupling-constant expression that is recently derived [Phys. Rev. A 85 (2012) 062508]. The proposed KE functional, which is called the “correlated Gaussian model”, consists of the modified version of the Thomas-Fermi (TF) model and correlation energy functional of the local density approximation. We check the validity of the correlated Gaussian model by means of numerical calculations for the Ne atom. It is shown that the correlated Gaussian model gives better results of not only the KE, Hartree energy, exchange-correlation (xc) energy, potential energy but also the xc-hole than the previously proposed correlated TF model [J. Phys.: Conference Series. 454 (2013) 012056].