INTEGRAL INVARIANTS FOR HIGH-SYMMETRY OPEN-SHELL MOLECULES - 1 - INVARIANT REPRESENTATIONS OF ELECTRON REPULSION INTEGRALS

A numerical procedure for expanding electron repulsion integrals [mm/n n] on degenerate molecular orbitals of gamma symmetry (gamma = e,t,g,h ) into integral invariants (reduced matrix elements) H-k(gamma,gamma) is suggested. The latter are analogous in their sense to Slater-Condon parameters F-k(l, l) for atoms with an electronic configuration IN. T he method is applicable to nonlinear molecules of arbitrary symmetries , including ''not readily reducible'' groups.