Rayleigh–Schrödinger perturbation theory for nonlinear Schrödinger equations with linear perturbation

Rayleigh–Schrödinger‐type perturbation theory is developed for the nonlinear Schrödinger equation, which contains a linear perturbation operator. Typical applications involve the self‐consistent reaction‐field model of solvent effects. Consideration of external perturbations, like electric fields, allows. Calculation of the response properties of solvated species. The general formulae allow development of a consistent Møller‐Plesset perturbation theory of solvated molecules.