A Comparison of the Super-CI and the Newton-Raphson Scheme in the Complete Active Space SCF Method

摘要: A density matrix formulation is presented of the super-C I and Newton-Raphson methods in complete active space SCF (CASSCF) calculations. The CASSCF method a special form MC-SCF method, where C wave function assumed to be subset orbital (the space), leaving remaining orbitals doubly occupied all configurations. Explicit formulas are given for elements first second derivatives formulation. similarities between two pointed out differences detailed formulations discussed. Especially interesting fact, that while can expressed terms order matrices, states involve also third some cases.