The molecular -factor

The experiment on ground state beat resonance was performed on tellurium Te2(X0+) [153] and later on K2(.X 1 +) [14, 34]. 

Other possible types of resonance are discussed in [4, 100]. Non-linear parametric, phase and relaxation resonances of quantum beats and the possibilities of their observation in molecules are considered in [33, 37]. 

As we have seen (Section 4.1), the behavior of the angular momentum J in a magnetic field is determined by the collinear magnetic moment pbj coupled with it. It is therefore important to consider the relation between the magnitudes of the magnetic moment /xj and the mechanical angular momentum J. This relation is, in its turn, determined by the Lande factor (the 5-factor), gj see (4.1). 

The magnetic energy (4.7) may be expressed through the molecular (/-factor gj as 

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The stability of the /Madam ring is strongly influenced by the molecular factors discussed above and, obviously, also by external factors such as biological fluids or pharmaceutical matrices. Some of these factors are discussed below. 

It should be noted that when replacing the London dispersive interactions term by other properties such as, for example, the air-hexadecane partition constant, by expressing the surface area in a more sophisticated way, and/or by including additional terms, the predictive capability could still be somewhat improved. From our earlier discussions, we should recall that we do not yet exactly understand all the molecular factors that govern the solvation of organic compounds in water, particularly with respect to the entropic contributions. It is important to realize that for many of the various molecular descriptors that are presently used in the literature to model yiw or related properties (see Section 5.5), it is not known exactly how they contribute to the excess free energy of the compound in aqueous solution. Therefore, when also considering that some of the descriptors used are correlated to each other (a fact that... 

The case of intermediate coupling of momenta (between Hund s cases (a) and (6)), as well as that of breaking weak field approximation axe discussed in [294]. The molecular (/-factors for Hund s case (c) coupling are discussed in [92, 364]. 

The weak-interaction Hamiltonian Hp in Eq. (8) acts only on the nucleon and the lepton coordinates, leaving the molecular ones unaffected. Consequently, in order to single out the molecular factor in the matrix element Eq. (8), it is necessary that the wave functions of nucleons and leptons be independent of the molecular variables The wave functions describe the motion of the nucleons inside the /eth nucleus with respect to its center of mass. The position of the latter is described by the radius vector R4, and, generally speaking, the wave functions depend both on Rk and on the internal nucleon coordinates. The wave function of the / electron produced in the final state must also depend on the center-of-mass coordinates of the nuclei. 

Numerous authors have devised multiple linear regression approaches to the correlation of solvent effects, the intent being to widen the applicability of the correlation and to develop insight into the molecular factors controlling the correlated process.For example, Zilian treated polarity as a combination of effects measured by molar refraction, AN, and DN. Koppel and Palm write... 

Monte Carlo simulations provide a rewarding and invaluable approach to solving these systems, and computer simulations and theory can isolate the molecular factors that control polyelectrolyte conformations in solution. Therefore, they are exU cmely useful to address the optimization of colloid-polymer mixtures and guide the design of new experiments. A simple model involving one chain interacting with one particle has been described, but the same model can be extended to more concentrated systems, e.g. involving several chains (and/or colloidal particles) with explicit counter ions, co-ions and solvent molecules. 

It is expected that future work along the routes outlined in this section will eventually lead to better comprehension of the molecular factors responsible for the phenomenon of hydrophobic interaction. 

The reorientational motions of molecules in the supercooled liquid state and in liquid-crystal-forming materials just above the clearing point may occur on a time-scale which is far longer than that encountered for normal low viscosity liquids. Such slow motions are conveniently studied using dielectric and dynamic Kerr-effect techniques in the ranges 10 to 10 Hz and 10" to lO s respectively. The present account describes the behaviour of representative systems, indicates the molecular factors which are involved and, where possible, gives a discussion of mechanisms for reorientation in specific liquid systems. 

The molecular factors controlling the Tg have been discussed at length elsewhere (Brydson, 1972) but a brief summary of these is given below. 

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