TRACE POLARIZABILITY SPECTRA FROM AR-2 QUASI-MOLECULES IN COLLISION-INDUCED SCATTERING

The experimental Ar-2 trace-polarizability collision-induced scatterin g spectrum is reported in absolute units range of Raman frequency shif ts, up to nu similar or equal to 400 cm(-1). At frequency shifts above 60 cm(-1), the measured spectral profile falls off exponentially. We were able to record the far wing down to intensities that are two orde rs of magnitude smaller than those of the previous work. While the lon g ago predicted insufficiency of the dipole-induced dipole (DID) or DI D-like trace models is confirmed, reliable fully quantum computations based on a modern approach show that the ab initio Dacre's trace [P. D . Dacre, Mol. Phys. 45, 1 (1982)] accounts well for the frequency depe ndence of the experimental spectrum differing only by a scaling consta nt.