Crossover from dynamic towards static line broadening in the classical mechanical vibrational photon echo

Abstract The vibrational echo measurement probes the time scales of dephasing processes that underlie a linear infrared absorption spectrum. We present calculations of the classical mechanical vibrational echo signal for a solvated anharmonic oscillator. The classical mechanical echo observable is shown to reveal the crossover towards static line broadening with the increase of solute anharmonicity, solvent time scale, or solute–solvent coupling strength.