The linear, quadratic, and cubic response of a multiconfigurational HartreeFock state to a time independent oneelectron perturbation has been derived. A comparison between the exact response functions as obtained from RayleighSchrdinger perturbation theory and the multiconfigurational HartreeFock response functions allows a identification of matrix elements of the perturbation operator between the ground and excited states and between excited states. We discuss some ambiguities which result from such an identification. Copyright 1983 John Wiley & Sons, Inc.
