Rayleigh-Schrodinger perturbation theory, Size consistency

The same strategy of deriving correlation corrections to CIS by Rayleigh-Schrodinger perturbation theory and adjusting size-incorrect terms can be extended to higher orders [61], The third-order correction consists of four terms ... [Pg.29]

Rayleigh-Schrodinger Perturbation Theory.—In Rayleigh-Schrodinger perturbation theory the unknown energy in the denominators of the Lennard-Jones Brillouin Wigner expansion is avoided. This enables a size-consistent theory to be derived. [Pg.7]

As an alternative to BriUouin-Wigner perturbation theory, we may consider Rayleigh-Schrodinger perturbation theory, which is size consistent. In this method, the total energy is computed in a stepwise maimer ... [Pg.647]