IDENTIFICATION OF 1-BODY, 2-BODY AND 3-BODY RAMAN-SCATTERING BY THE FIELD GRADIENT INDUCED DIPOLE-A TENSOR IN METHANE

In previous work involving the nu1 mode, Raman depolarization ratio (R DR) density dependent studies of supracritical methane, 10% methane in carbon dioxide, and 10% methane in argon, the present authors had hyp othesized that the Coriolis coupling and resulting dipole moment playe d a leading role in the explanation of the RDR versus density (pressur e) dependence found. This was necessitated by the fact that we could f ind no direct evidence for interaction induced ii, i.e., 2-body and 3- body light scattering. That evidence has now been identified from the previously recorded pure methane data and is the subject of this paper . It should be noted, however, that this current interpretation revers es the previous arguments for angular dependent intermolecular couplin g as a contributing factor in addition to translational ii in explaini ng the earlier RDR results.