Electron–hole generations: a numerical approach to interacting fermion systems

A new approach, motivated by Fock space localization, for constructing a reduced many-particle Hilbert space is proposed and tested. The self-consistent Hartree–Fock approach is used to obtain a single-electron basis from which the many-particle Hilbert space is constructed. For a given size of the truncated many particle Hilbert space, only states with the lowest number of particle–hole excitations are retained and exactly diagonalized. This method is shown to be more accurate than previous truncation methods, while there is no additional computational complexity.