Of symmetrical top molecule

St. Pierre A. G., Steele W. A. Collisional effects upon rotational correlations of symmetrical top molecules. J. Chem. Phys. 57, 4638-48 (1972). 

The above results may be extended to electronic transitions in the case of symmetric top molecules [156, 374, 402], where, in molecule-fixed coordinates, the rotational state of the molecule is characterized by two values, namely the modulus (J) of the total angular momentum, and the projection (K) of the momentum J on the symmetry axis of the molecule (the x-axis see Fig. 1.4). In the case of an electronic transition where... 

Kramer, K.H. and Bernstein, R.B. (1965). Focusing and orientation of symmetric-top molecules with the electric six-pole field, J. Chem. Phys., 42, 767-770. 

The following section contains a more detailed treatment of the theory behind the nonresonant spectroscopy of liquids. This will be followed by a description of the experimental implementation and data analysis techniques for a common OKE scheme, optical-heterodyne-detected Raman-induced Kerr-effect spectroscopy (22). We will then discuss the application of this technique to the study of the temperature-dependent dynamics of simple liquids composed of symmetric-top molecules. 

WKB-phase shifts are used for the isotropic part of the potential and phase shifts in the sudden limit for the anisotropic part (Cross, 1967) produced cross sections which are also in quantitative agreement with the experimental results (Buck et al., 1975). It proved necessary to introduce a large P,-contribution to the potential in order to get this agreement for the scattering of symmetrical top molecules on atoms. Thus this type of measurements seems to provide a reliable method for the determination of the anisotropic part of the potential. 

In a certain respect the einalysis of the rotational Zeeman effect may appear simpler in the case of symmetric top molecules as compared to the asymmetric top case, since the angular momentum eigenfunctions with K... 

Fig. III. 14. The effect of the translational Zeeman effect on the absorption spectra of symmetric top molecules moving at different velocities perpendicular to the exterior magnetic field is shown for the J = - J = 2, K =l rotational transition of methylacethylene (l Oj. = 0, 100, 200,. 800 m/sec). With increasing velocity the aligning force of the Lorentz cross field...

This submatrix is used in the discussion of the translational Zeeman effect of symmetric top molecules (see Chapter II). 

Appendix 7.B An Alternative Treatment of Symmetric Top Molecules, 151 Appendix 7.C Irreducible Tensors in Light Scattering, 157... 

Symmetric Top, Ia - Iq (prolate top) or Ia=Ibrotational spectrum is still degenerate in the nij quantum number however, part of the k degeneracy is lift. Only those levels with k =0 are now doubly degenerate (in k). The rotational spectrom of symmetric top molecules (such as NH3, CgHg) can be written as... 

In the intermediate region (3 < X < 5) both effects are significant. Gillen and Noggle [127] apply these principles to experimental data for a number of symmetrical-top molecules. As can be seen from Fig. 

In favorable cases, the analysis of the rotational spectrum of symmetric top molecules in vibrational state Vi... Vy... t)3N-6 allows the determination of the constants listed in this table. The rotation-vibration interaction constants are determined by the analysis of at least two vibrational states of the same normal vibration. 

Parallel and perpendicular IR bands of symmetric top molecules (a) parallel band of CD3F and (b) perpendicular band of GeClHs- Spectrum (a) is taken, Redrawn from Modem Spectroscopy, 4th Edition, J. Michael Hollas. Copyright 2003 John Wiley Sons. 

St. Pierre AG, Steele WA (1972) Collisional effects upon rotational correlations of symmetric top molecules. J Chem Phys 57(ll) 4638-4648... 

Lascombe J, Besnard M, Maraval P (1982) A new extended diffusion-model for rotational motion of symmetric-top molecules in the liquid-phase. Chem Phys 72(1-2) 177-184. doi 10.1016/0301-0104(82)87078-x... 

A new molecular beam machine has been constructed at UCLA with a 3m electrostatic hexapole field for the production of intense, pulsed beams of essentially pure JKM> states of symmetric top molecules [54]. Figure 1 shows a couple of so-called "focusing curves" for CH3CI molecules... 

There are theoretical procedures in use in the literature which have led to accepted definitions of parameters characteristic for a molecule under consideration. The underlying expressions will be given here. It is aimed at that the reader is provided with sufficient information to calculate, at least in principle, the pertinent energetic stmctures of symmetric-top molecules with the aid of the parameter listings given in this sub-volume. The knowledge of the appropriate selection rules is then necessary for the prediction of spectra. 

In favorable cases, the analysis of the rotational spectrum of symmetric top molecules in vibrational state... 

Spherical-Top Molecules The rotational energy expression of symmetric-top molecules is the same as that of a linear molecule. However, it has to be noted that, even if the energy... 

Ref p. 20] 2.6.3.1 Dipole moments of symmetric top molecules Preliminary remarks... 

Ref p. 89] 2.7.3.1 Quadrapole coupling constants of symmetric top molecules Preliminaiy remarks 87... 

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