Resolvent Operator Formulation of Stationary State Perturbation Theory
Robert Yaris · The Journal of Chemical Physics · 1964
By starting with an exact operator equation and using different methods of expanding the resolvent operator, the Schrödinger, Wigner—Brilloin, similarity transformation, gauge transformation, and first-order perturbation iteration method, perturbation expansions are generated in a rigorous and straightforward manner. It is also shown how additional perturbation and perturbation iteration methods can be generated.