From light-scattering measurements to polarizability derivatives in vibrational Raman spectroscopy: The 2ν5 overtone of SF6

摘要: The room-temperature isotropic spectrum of SF6 was recorded at the frequency 2ν5 overtone by running high-sensitivity incoherent Raman experiments for two independent polarizations incident beam and gas densities varying from 2 to 27 amagat. Weak yet observable pressure effects were found. A transparent analysis cross-section problem along with first-ever prediction value mean polarizability second derivative ∂2α¯/∂q52 are made hitherto underestimated role hot bands is brought wider public. emergence an analytic hotband factor shown whose magnitude dramatically increased order temperature all more so upon considering low-frequency molecular vibrations. Our formulas, which in harmonic approximation exact, still applicable real situations provided certain conditions fulfilled. For nondegenerated modes, generalization higher overtones made, ...