The first four moments of the spectral density distribution of an N-electron Hamiltonian matrix defined in an antisymmetric and spin-adapted model space

Expressions for the first four moments of the spectral density distribution of a Hamiltonian matrix describing a system of N spin 1/2 particles are tabulated. The Hamiltonian matrix is defined in a model space of antisymmetrized products of spinorbitals combined to form eigenfunctions of the total spin operators. The moments are given as explicit functions of the interaction integrals and of three integers describing the space (the total number of particles, the total number of orbitals, the total spin quantum number). (C) 1995 Academic Press, Inc.