The Enskog theory for classical vibrational energy relaxation in fluids with continuous potentials

The recently developed Enskog theory for binary friction for fluids with co ntinuous potentials, such as the Lennard-Jones, has been extended to calcul ate the frequency dependence of this friction. zeta (E)(omega)- This zeta ( E)(omega) is then applied to study vibrational energy relaxation of low-fre quency modes via the Landau-Teller expression. The agreement with simulatio n results is found to be satisfactory. In the present approach we provide a n exact prescription for the binary friction and thus remove a lacuna in th is area. zeta (E)(omega) shows an interesting structure with a hump at low frequency, the signature of which has already been seen in many simulation studies. (C) 2001 American Institute of Physics.