Density-functional formula for strongly correlated systems

Up to now, computation method dealing withthe many electron systems has been based on single particle approximation. That is to say, the wavefunctions of a system are composed of single particlewave functions (SPWF’s), and all the physical prop erties are determined by the SPWF’s. There havebeen two sophisticate techniques to solve the SPWF’s.One is the well known Hartree Fock self consistent e quations (HFSCE). The other is the Kohn Sham e quations of density funct…

Density-functional formula for strongly correlated systems

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.