Anisotropic collision-induced Raman scattering by the Kr:Xe gas mixture

Abstract

We report anisotropic collision-induced Raman scattering intensities by the Kr-Xe atomic pair recorded in a gas mixture of Kr and Xe at room temperature. We compare them to quantum-mechanical calculations on the basis of modern incremental polarizability models of either ab initio post-Hartree-Fock or density functional theory methods.

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

“…Description in detail of the equipment and of the way we are used to operate has been given previously. 13,14,17,60,61 Technical details, related to the way in which the 2ν 5 signal was isolated from its environment and to how a densityindependent absolute-calibrated isotropic spectrum was extracted from the recorded spectrum, will be skipped. In what follows, only the essentials of the isotropic spectrum are gathered.…”

“…Although such values are too low a performance in comparison to some of today's feats of instrumentation, [10][11][12] it is sometimes the cost of the effort required to maximize sensitivity, as in the case of the very high-sensitivity Raman equipment of our institute. [13][14][15][16][17] To make things concrete, let us take SF 6 and its 2ν 5 Raman overtone. This molecule has been witnessing rea) Electronic mail: michel.chrysos@univ-angers.fr newed spectroscopic interest in the last two decades, [18][19][20][21][22][23][24][25] with its role in environmental and atmospheric issues being among the reasons for concern.…”

More light on the 2ν5 Raman overtone of SF6: Can a weak anisotropic spectrum be due to a strong transition anisotropy?

“…Only with the use of two independent polarizations for the incident beam in running independent Raman experiments can those two quantities be determined safely, and our group has developed, since more than a decade ago, protocols following such a strategy to increase reliability. [25][26][27][28][29] While the polarized I ⊥ component of the 2ν 5 SF 6 overtone, treated in the previous works, 21,22 can to some extent be considered as a rather reasonable approximation of the overtone's isotropic spectrum, the latter spectrum had to await, for its rigorous analysis, a study made recently by our group. 23 In contrast, none of the previous treatments has ever mentioned anything about some anisotropic spectrum for that overtone.…”

The 2ν3 Raman overtone of sulfur hexafluoride: Absolute spectra, pressure effects, and polarizability properties

“…31,[34][35][36][37] In the present study, we ran, for each polarization of the incident beam, 10 independent experiments for the following 10 values of gas density: 2, 3, 5, 7, 9, 11, 13, 15, 17, and 19 amagat (i.e., for gas pressures amounting to 2.13, 3.15, 5.12, 6.98, 8.74, 10.40, 11.95, 13.41, 14.77, and 16.03 bars). Calibration of the Raman signals on an absolute scale was made by means of the S 0 (1) rotational line of molecular hydrogen, ensuring, for each value of ρ, conversion to absolute spectral quantities S i (ρ, ν) (with i = ⊥ or ) and I i (ν) = S i (ρ, ν)/ρ (measured in units of cm 3 amagat and cm 3 , respectively).…”