The influence of nonadiabatic rotational transitions on the line shapes of the rotational Raman spectrum of H2 in liquid argon

Abstract

General expressions for time correlation functions of operators of a quantum subsystem being driven by a classical solvent are derived in the limit that the forces on the classical solvent from the quantal solute are independent of the state of the quantum subsystem [the zero back reaction (ZBR) limit]. These expressions are used to compute the rotational Raman spectrum of a quantal H₂ rotor in liquid argon whose motion is described by nonadiabatic transitions between orientational sublevels resulting from solvent collisions. Line shapes computed in both the static and adiabatic limits are compared with those computed allowing for nonadiabatic transitions in an effort to understand the influence of these transitions on the spectrum.