Natural orbital functional theory and pairing correlation effects in electron momentum density

Articles you may be interested in Excitation energies with linear response density matrix functional theory along the dissociation coordinate of an electron-pair bond in N-electron systems The flexible nature of exchange, correlation, and Hartree physics: Resolving " delocalization " errors in a " correlation free " density functional Density functional theory embedding for correlated wavefunctions: Improved methods for open-shell systems and transition metal complexes Occupation numbers of natural orbitals capture the physics of strong electron correlations in momentum space. A natural orbital density functional theory based on the antisymmetrized geminal product provides these occupation numbers and the corresponding electron momentum density. A practical implementation of this theory approximates the natural orbitals by the Kohn–Sham orbitals and uses a mean-field approach to estimate pairing amplitudes leading to corrections for the independent particle model. The method is applied to weakly doped La 2 CuO 4 .