The restricted active space followed by second-order perturbation theory method: Theory and application to the study of CuO(2) and Cu(2)O(2) systems.
A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturb
