POLARIZATION SELECTIVITY OF NONRESONANT SPECTROSCOPIES IN ISOTROPIC MEDIA

We present an analysis of the contributions of of the first- and secon d-derivative tensors of the many-body polarizability to third-and fift h-order nonresonant spectroscopies in isotropic media. Collision-induc ed effects are shown to have a notable influence on the second-derivat ive polarizability tensor (Pi((2))) for intermolecular modes. As a res ult, polarization selectivity in nonresonant. intermolecular spectrosc opies can be achieved in fifth-order spectroscopies. Additionally, ter ms in fifth-order spectroscopy that arise from three interactions thro ugh Pi((2)) may not be negligible in many liquids. Our analysis shows that there exists no straightforward relationship between the observab les in third-and fifth-order intermolecular spectroscopies. The predic tions of this analysis are tested against the available experimental d ata for CS2. (C) 1997 American Institute of Physics. [S0021-9606(97)51 947-7].