Brillouin's Theorem

Approximate wave functions can be determined in many different ways. By solving the Hartree-Fock equations, the single-configuration Hartree-Fock approximation has some special properties not possessed by other approximations. One such property is referred to as satisfying Brillouin's theorem (Brillouin 1932, 1934), though we will show that Brillouin's theorem is not always obeyed.
 

2001-01-09