Raman depolarization

Present formal definitions of intensities and Raman depolarization ratios,... 

A frequency job begins by computing the energy of the input structure. It then goes on to compute the frequencies at that structure. Gaussian predicts the frequencies, intensities, and Raman depolarization ratios and scattering activities for each spectral line ... 

Raman scattering activities (A 4/AMU), Raman depolarization ratios. 

The moments are determined experimentally as for nitrogen in [5, 106] using Rayleigh and Raman depolarized scattering spectra. 

De Santis A., Sampoli M., Morales P, Signorelli G. Density evolution of Rayleigh and Raman depolarized scattering in fluid N2. Mol. Phys. 35, 1125-40 (1978). 

Raman depolarization ratio Time-scale of relaxation among three sublevels in p-state... 

The molecular symmetry of octahydropyridazino[ 1,2-a ]pyridazine (24) has been analyzed using band numbers, frequency coincidences and Raman depolarization factors in the IR and Raman spectra. A centrosymmetric trans conformation was confirmed for this compound (76SA(A)157). IR spectral data also indicate that the carbonyl absorption for pyridazino[l,2-a]pyridazine-l,4-diones (26) occurs at ca. 1625 cm-1 (72TL1885). 

Raman scattering activities (A 4 /AMU), Raman depolarization ratios, reduced masses (AMU), force constants (mDyne/A) and normal coordinates ... 

Symbols p— Raman depolarization ratio, r - correlation coefficient... 

Fig. 11.6. Bar graphs of the mean Raman depolarization ratio calculated from the parallel- and cross-polarized intensities of the 959 cm 1 PO43- peak. Data were obtained from 47 (sound) and 27 (caries) PRS measurements on 23 extracted teeth. Student s t-test analysis reveal p <0.001. Error bars show standard deviation...

One of the first VCD studies we undertook in 1988 was work on the tripeptide L-Ala-L-Ala-L-Ala [23], This molecule, in neutral aqueous (D O) solution, exhibits a distinct, near-conservative VCD spectrum in the amide I region, shown in Figure 7. The infrared absorption shows two overlapping peaks in the amide I region, at 1650 and 1675 cm 1. Raman depolarization ratios indicated that the high frequency component is the symmetric stretching combination. 

Raman Depolarization Ratio. A more complete discussion of vibrational selection rules must take into account the vector properties of the dipole moment and the tensor character of the polarizability a. Thus Eq. (1) should be written... 

The general approaches used in the studies considered below for assignment of the observed vibrational bands to the short-lived molecules are analogous to those described in Sections III and IV. The assignment of the revealed bands to normal, or fundamental, vibrational modes has been based on taking into account selection rules, observations of the bands in characteristic regions, observations of isotopic shifts, results of depolarization measurements in the Raman spectra and results of normal coordinate analysis. (It is noteworthy that Raman depolarization measurements can be conducted for matrix isolated species as well see Reference and references cited therein.) Lately, quantum-chemical calculations of vibrational spectra have become an important tool for both identification of CAs and assignment of their vibrational spectra. 

Figure 8 Schematic layout of a typical 90° Raman depolarization experiment showing the positions of the polarization analyzer and the scrambler. The analyzer may simply be a polaroid sheet, which can be rotated by 90° to allow the parallel ( ) and perpendicular ( ) components of the scattered light to pass through to the detector. The function of a scrambler is to change linear into circular polarization of the light entering the Raman spectrometer slit in order to avoid measurement errors due to the variable spectrometer transmittance of the light polarized in different directions...

R. L. Rowell, G. M. Aval, and J. J. Barrett. Rayleigh-Raman depolarization of laser light scattered by gases. J. Chem. Phys., 54 1960-1964 (1971)... 

M. Thibeau, A. Gharbi, Y. Le Duff, and V. Sergiescu. A comparative study of Rayleigh and Raman depolarized light scattering by a pure fluid of isotropic molecules. J. Phys. (Paris), 55 641-651 (1977). 

M. Thibeau. Rayleigh and Raman Depolarized Light Scattering by Isotropic Molecules. In B. Vodar and Ph. Marteau, (eds.). High Pressure Science and Technology, Pergamon, New York, 1980, pp. 724-726. 

V. Sergiescu. On the usefulness of the lattice-gas model in the theory of the DID Rayleigh and Raman depolarized scattering by a fluid of isotropic molecules. Physica C, 97 292-298 (1979),... 

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