A molecular dynamics simulation of dephasing in liquid nitrogen. II. Effect of the pair potential on dephasing

Abstract

We carry out a computer simulation of vibrational dephasing in liquid nitrogen near its boiling point using a multiparameter potential which includes short range valence, dispersion, and quadrupole interactions. The effect of vibration–rotation coupling on the line shape is also included in the calculation. The isotropic Raman line shift obtained is −5 cm⁻¹ while the dephasing time T₂ (inversely proportional to the linewidth) is 100±10 psec. It is shown that there is substantial cancellation between repulsive and attractive contributions to the linewidths, so that the Raman spectrum is very sensitive to details of the molecular interactions.