Ab initio collision-induced polarizability, polarized and depolarized Raman spectra, and second dielectric virial coefficient of the helium diatom
Symmetry-adapted perturbation theory has been applied to compute the interaction-induced polarizability for the helium diatom. The computed polarizability invariants have been analytically fitted, and used in quantum-dynamical calculations of the binary collision-induced Raman spectra. The predicted intensities of the depolarized spectrum are in good agreement with the experimental data [M.H. Proffitt et al., Can. J. Phys. 59, 1459 (1981)]. The computed polarized spectrum shows agreement with the experiment within the large experimental uncertainties. The calculated trace polarizability was also checked by comparison of computed second dielectric virial coefficients with the experimental data. The ab initio dielectric virial coefficients, including first and second quantum corrections, agree well with the experimental data from indirect measurements.