Raman excitation profiles with self-consistent excited-state displacements

Raman excitation profiles (REPs) are computed in the time domain for harmon ic modes with excited-state displacement g and measured at multiple excitat ion frequencies omega (L) in a bimetallic complex with a metal-to-metal cha rge-transfer band and 10 coupled modes. Self-consistency is required becaus e the time evolution depends on all displaced modes rather than the individ ual intensities used in the short-time approximation for g((0)),. Self-cons istency ensures that g is independent of wt for a single resonance. Exact R EPs for displaced oscillators show the importance of vibronic lifetimes and marked deviations from the short-time approximation ac. molecular frequenc ies. Spectra at multiple wt indicate scattering from another electronic exc itation with displacement h that is also found self-consistently. Mode-spec ific Raman data at multiple wt require additional parameters to yield relia ble structural information. Harmonic oscillators with self-consistent displ acements are a first approximation to systems with many coupled modes.