Note on the Exchange Polarization and In-Out Effect

Abstract

To investigate the correlation of electrons in the same shell due to the exchange correlation with the other unpaired electron, and so-called in-out effect, several approximate methods (Hartree-Fock, unrestricted Hartree-Fock, projected unrestricted Hartree-Fock, split shell and spin degenerate state configuration interaction) are developed. As the simplest example, the ground state ²S and first excited state ²P of the Li atom are considered. Slater type 1s, 2s, and 2p orbitals are adopted and the wave functions and total energies are determined by the variational method. The electron spin density at the nucleus (ψ²(0)) is given for the respective cases. Discussions on the results are given.