Quadrapole interaction

Quadrapole interactions-symmetrical molecules with atoms of different electronegativities, such as CO2 possess no dipole moment but... 

The first two terms, which have been discussed in detail up to this point, dominate. Note the term Z]Z2e /47T Q in Eq. (2.13) is a constant replaced by A in Eq. (2.19). The term in parentheses represents dipole-dipole and dipole-quadrapole interactions between the ions. The last term represents the zero-point correction, with i ax being the highest frequency of the lattice... 

Higher level quadrapole interactions, which tend to increase the attractive interaction, are not considered. 

Fig. 2.4 In the case of a non-zero electric field gradient (EFG), electric quadrapole interaction as visualized by the precession of the quadrupole moment vector about the field gradient axis sets in and splits the degenerate I = 3/2 level into two substates with magnetic spin quantum numbers mi = 3/2 and 1/2. This gives rise to two transition lines with equal probability (intensity). The energy difference between the two sub states AEq is observed in the spectrum as the separation between the two resonance lines...

The value of 100 cal mole chosen for the adsorption energy of helium is consistent with the fact that helium has no dipole or quadrapole and is only slightly polarizable. Thus, it will minimally interact with any surface. Based upon reflections of a helium beam from LiF and NaCl cleaved surfaces, de Boer estimated the adsorption energy to be less than 100cal mole i. 

Quadrapole ion interaction, deduced, 211, Reaction equilibria, in low melting point liq-... 

Generalizations [71] of the bare anisotropic-planar-rotor model (2.5) include other multipolar interactions such as dipolar and octopolar terms with and without in-plane crystal-field modulations. Several such combinations were analyzed in the mean-field approximation, Landau theory, and spin-" wave expansion [71]. The quadrapole-quadrupole model written in the form... 

It is interesting to note that one of the first measurements of the electric nuclear quadrapole moment of S was made by Bird and Townes who on close examination of Solimene and Dailey s microwave spectrum of methanethiol noticed a group of three very weak doublets. They ascribed the doublets to the interaction of the electric quadrupole moment of natural abundance with the electric field of the molecule as a whole. 

S = quadrupolar nucleus J = magnetogyric ratio 0 = angle between main tensor axes d = chemical shift tj = relaxation time = angle between main axes of interaction tensors and sample spinning axis X = quadrapole coupling constant. 

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