Raman depolarization ratio

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. 

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

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... 

Figure 9 Polarized Raman measurements are used to characterize grain orientation in polycrystalline films. (A) Principal Raman vibrational modes for the rutile phase of Ti02 (B) Polarized Raman spectra of oriented films (order increases from top to bottom) (C) Refractive index variation with Raman depolarization ratio for the A q mode.

Raman depolarization ratios of the H2O molecule with various basis sets. 

Raman Depolarization Ratio. Thomley and Shepherd suggest that measuronent of Raman depolarization ratios (p) offer a sensitive probe for polymer conformations and yields valuable information even in concentrated solutions where, in contrast to other techniques, it does not suffer from difficulties of either measurement or interpretation. They use computations of the probability of a rotational isomer being trans in order to relate/> to free energy of mixing for poly(dimethyl siloxane)-benzene. 

All 3N - 6 normal modes (Cartesian displacements for each atom) are then listed, together with as much information for each mode as is available, depending on which, if any, of the dipole derivatives, the polarizability derivatives or the rotational strengths have been computed for the molecule in question. For trans-l,2-dichloroethane all these quantities are available except the latter, so listed for each mode is its symmetry type, its frequency in wavenumbers (cm ), whether or not the mode is IR active, the corresponding IR intensity, the X, Y and Z dipole derivatives with respect to the motion in each normal mode, whether the mode is Raman active, its corresponding Raman intensity and its Raman depolarization ratio. If the molecule were VCD active, its rotational strength (relative intensity in a VCD spectrum) would also be printed. 

RS is a polarized effect and the assignment of Raman bands to the vibrations in a molecule can be obtained by analysing the scattered light parallel and perpendicular to the incoming E vector. It can be done by the Raman depolarization ratio ... 

Analytic derivative calculations of Raman intensities and Raman depolarization ratios for H2O, NH3, CH4 and C2H2 have been reported by Amos [175,189]. The author... 

The spectra are dominated by molecular z ( c)-polarized absorption. The extremely intense 394 nm solution band is z-polarized, as indicated by the fact that we could scan well past 400 nm in c polarization. This conclusion is consistent with Clark s [17] determination of z-polarization for this band in solution via resonance Raman depolarization ratio measurements. Stealing intensity from this band is likely to be the dominant intensity-giving mechanism for the weak bands. 

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