Development of Kinetic Energy Density Functional Using Response Function Defined on the Energy Coordinate
Abstract
A kinetic energy functional Ee was developed within the framework of the densityfunctional theory (DFT) based on the energy electron density for the purpose of realizing the orbitalfree DFT. The functional includes the nonlocal term described with the linearresponse function (LRF) of a reference system. As a notable feature of the present approach, the LRF is represented on the energy coordinate {\epsilon} defined for each system of interest. In addition, an atomic system is taken as a reference system for the construction of the LRF, which shows a clear difference from the conventional approach based on the homogeneous electron gas. The explicit form of the functional Ee was formulated by means of the couplingparameter integration scheme. The functional Ee kin kin was applied to the calculations of the kinetic energies of the pseudo atoms that mimics H, He, Ne, and Ar. Explicitly, the kinetic energy of each atom was computed using the functional Ee with respect to the variation of the valence charge Zv of each atom. In these calculations, the electron density n optimized by the KohnSham DFT was adopted as an argument of the functional. It was found that the results are in excellent agreements with those given by the KohnSham DFT. We also devised a method to perform the selfconsistent field calculation utilizing the functional Ee . kin The method was applied to the computation of the radial distribution functions of the electrons in the pseudo Ne and Ar atoms. It was demonstrated that the results reasonably agree with those yielded by the KohnSham DFT.
 Publication:

arXiv eprints
 Pub Date:
 October 2021
 DOI:
 10.48550/arXiv.2110.02041
 arXiv:
 arXiv:2110.02041
 Bibcode:
 2021arXiv211002041T
 Keywords:

 Physics  Computational Physics
 EPrint:
 15 pages, 7 figures