| Semiclassical initial value representation calculations are presented of vibrational relaxation in model harmonic and anharmonic oscillator systems bilinearly coupled to a dissipative harmonic bath. Analogous to the standard classical treatment, the continuum limit properties of the discrete bath may be invoked giving rise to a generalized Langevin equation for the system degrees of freedom except the noise term is of quantum origin. Combining this development with other recent advances in semiclassical dynamics leads to a highly tractable computational scheme for thermal correlation functions. Simulations of vibrational relaxation in the harmonic oscillator system are presented along with the corresponding exact quantum mechanical results demonstrating that the semiclassical results are quite accurate over a wide range of temperature and friction. In the strong damping regime, the first order correction term in the series representation of the propagator is also calculated providing a systematic approach for improvement of the semiclassical approximation. Similar calculations are performed to measure the temperature relaxation of an excited Morse oscillator. |
|