Vibrational spectroscopy of HOD in liquid D_2O. IV. Infrared two-pulse photon echoes

摘要

Using molecular dynamics simulation and the self-conssitent renormalization scheme for liquid-state vibrational spectrosocpy developed earlier by us, we have calcualted the infrared integrated two-pulse photon echo signal for the OH stretch of dilute HOD in D_2O at 300 K. Our echo decay time of 37 fs is in good agreement with the experimental value of 33 fs. The experiment was originally analyzed in terms of a model with both homogeneous and inhomogeneous broadening. The parameters from this analysis are in reasonable agreement with those from our theory. Nonetheless, a critical assessment of this analysis raises some questions about i8ts quantitative accuracy.