Electron and nuclear density matrices and the separation of electronic and nuclear motion

Abstract

AbstractThe so‐called parametric dependency of the electronic wave function in the Born–Oppenheimer approximation is discussed. Considering a function beyond this approximation, a new set of equations is derived with parametric and nonparametric dependency. Nuclear and electron reduced density matrices are introduced in this derivation. They are used in a formulation of the problem of separation of nuclear and electronic motion.