Journal of Chemical Physics, Vol.100, No.5, 3672-3682, 1994
Considerations in Constructing a Multireference 2nd-Order Perturbation-Theory
Several possible definitions for a multireference second-order perturbation theory are suggested. These are tested against some standard test problems from the literature.
Keywords:GENERALIZED MOLLER-PLESSET;OPEN-SHELL SYSTEMS;COUPLED CLUSTER THEORY;CORRELATION-ENERGY;ELECTRONIC STATES;DIFFERENT FORMS;WAVE-FUNCTIONS;BK METHOD;MOLECULES;CONVERGENCE