Rotational coupling

The only tenn in this expression that we have not already seen is a, the vibration-rotation coupling constant. It accounts for the fact that as the molecule vibrates, its bond length changes which in turn changes the moment of inertia. Equation B1.2.2 can be simplified by combming the vibration-rotation constant with the rotational constant, yielding a vibrational-level-dependent rotational constant. 

D. Perturbative Treatment of Vibration-Rotation Coupling III. Rotation of Polyatomic Molecules... 

QUANTUM MONODROMY AND MOLECULAR SPECTROSCOPY A. Spin-Rotation Coupling... 

The simplest example of angular momentum coupling is provided by the scaled spin-rotation coupling Hamiltonian... 

Recently, we have developed a full theoretical treatment of electron capture processes involving an ab initio molecular calculation of the potential energy curves and of the radial and rotational couplings followed, according to the collision energy range concerned, by a semi-classical [21-23] orquantal [24] collision treatment. 

The rotational coupling matrix elements between Z-IT and fl-A states have been evaluated analytically by use of the L. and L. operators. 

Fig. 3. Rotational coupling matrix element between the ll (N (3p) + He (ls)) state and the states of single-electron capture.

Restriction equations, molecular systems, component amplitude analysis, reciprocal relations, 215-217 Robb, Bemardi, and Olivucci (RBO) method, conical intersection location, 489—490 Rotational couplings ... 

Fig, 19. Infrared spectra of the symmetric CHj bend mode of ethylidyne (CCHj) on Pt(l 11) at 82 K and 300 K. The dotted lines are calculated assuming a vibrational-rotational coupling. Inset shows the suggested orientation. (Reproduced by permission from Malik et... 

This is, however, only the contribution of a rigidly rotating distribution of electrons and predictions of the g factor based on this expression [41,42] do not agree with the experiment [42]. It is therefore necessary to take into account that the motion of the electrons is perturbed by the rotation of the molecule [16 17,42], i.e., electronic motion and molecular rotation couple through which... 

An important theoretical development for the outer-sphere relaxation was proposed in the 1970s by Hwang and Freed (138). The authors corrected some earlier mistakes in the treatment of the boundary conditions in the diffusion equation and allowed for the role of intermolecular forces, as reflected in the IS radial distribution function, g(r). Ayant et al. (139) proposed, independently, a very similar model incorporating the effects of molecular interactions. The same group has also dealt with the effects of spin eccentricity or translation-rotation coupling (140). 

It should be noted that the spacings between the experimentally observed peaks in HC1 are not constant as would be expected based on the above P- and R- branch formulas. This is because the moment of inertia appropriate for the v = 1 vibrational level is different than that of the v = 0 level. These effects of vibration-rotation coupling can be modeled by allowing the v = 0 and v = 1 levels to have rotational energies written as... 

---