Collision-induced hyper-Rayleigh spectrum of octahedral molecules:: The case of SF6

A theoretical expression giving the collision-induced hyper-Rayleigh (CI HR) spectrum due to pairs of centrosymmetric molecules of octahedral symmetry has been derived. The dipole2-quadrupole hyperpolarizability light scattering mechanism of collision-induced hyperpolarizability Delta beta (LM) is discussed in detail and proposed to explain the CI HR spectrum. Numerically we have applied our analytical formulas to binary CI HR spectrum of sulfur-hexafluoride. We have normalized our SF6 CI HR spectrum to the monomer HR spectrum of CCl4. The spectral contribution due to second hyperpolarizability-permanent hexadecapole HR light scattering mechanism has been estimated and showed to be negligible. (C) 2001 American Institute of Physics.