Extended HartreeFock method based on pair density functional theory
Abstract
A practical electronic structure method in which a twobody functional is the fundamental variable is constructed. The basic formalism of our method is equivalent to HartreeFock density matrix functional theory [M. Levy, in Density Matrices and Density Functionals, edited by R. Erdahl and V. H. Smith, Jr. (Reidel, Dordrecht, 1987)]. The implementation of the method consists of solving HartreeFock equations and using the resulting orbitals to calculate twobody corrections to account for correlation. The correction terms are constructed so that the energy of the system in the absence of external potentials can be made to correspond to approximate expressions for the energy of the homogeneous electron gas. In this work, the approximate expressions we use are based on the highdensity limit of the homogeneous electron gas. Selfinteraction is excluded from the twobody functional itself. It is shown that our pair density based functional does not suffer from the divergence present in many density functionals when homogeneous scaling is applied. Calculations based on our pair density functional lead to quantitative results for the correlation energies of atomic test cases.
 Publication:

Physical Review B
 Pub Date:
 April 2008
 DOI:
 10.1103/PhysRevB.77.155110
 arXiv:
 arXiv:0804.1058
 Bibcode:
 2008PhRvB..77o5110H
 Keywords:

 71.10.w;
 31.15.V;
 31.15.xr;
 31.30.i;
 Theories and models of manyelectron systems;
 Electron correlation calculations for atoms ions and molecules;
 Selfconsistentfield methods;
 Corrections to electronic structure;
 Condensed Matter  Other;
 Condensed Matter  Materials Science
 EPrint:
 to appear in Physical Review B