GENERALIZED SCHRODINGER EQUATIONS FOR SHIFTS, WIDTHS, AND WAVE FUNCTIONS OF ATOMIC AND MOLECULAR STATES IN DENSE MATTER

Abstract

There are a variety of approaches to the definition and calculation of wave functions of atoms and molecules immersed in a perturbing medium. These include (1) the self-consistent field method, (2) the microfield method, (3) the Bethe-Salpeter equation, (4) determination of the discrete eigenfunctions of an appropriate reduced density matrix, and (5) variational methods based on the existence of bound-state poles of appropriate Green's functions and the dependence of the positions of these poles on the bound state wave functions. After brief review of approaches (1)–(4) with emphasis on their limitations, the approach (5), which leads to generalized Schrodinger equations for simultaneous determination of shifts, widths, and wave functions of medium-perturbed bound states, will be described in more detail. This approach makes use of Liouville-space methods and is sufficiently general to encompass both equilibrium and nonequilibrium states of the medium. Some explicit results are obtained for a partially ionized hydrogen plasma.