Predissociation gyroscopic

The selection rules and v, J-dependence of predissociation effects depend on the identity of the operator responsible for the predissociation. From knowledge of the selection rules, qualitative information can immediately be obtained from the variation of the total interaction with v or J. For example, if lines from low-7 levels are missing in emission, the predissociation is certainly not due to a gyroscopic (Afi 0) interaction, which would be zero for J = 0, but must arise from a homogeneous (Afl = 0) interaction. 

The first example of hyperfine predissociation appears simultaneously with gyroscopic predissociation in the I2 B3no+ state (Broyer, et al., 1976). The predissociation due to gyroscopic coupling is very small in this particular case. Taking its effect into account, a residual effective radiative lifetime (nonzero for J = 0) has been found that shows a strong variation with v. This is actually a... 

Even more so than for perturbations, the isotopic dependence of predissociations is useful for identifying the electronic symmetry of the unbound state. The naive assertion that the lightest isotopic molecule is predissociated most rapidly must be examined with caution. It is valid only in the cases of gyroscopic predissociation and predissociation by rotation through a centrifugal barrier. In Eq. (7.5.17), the matrix element... 

The isotope effect on differential Franck-Condon factors has been investigated by Child (1974) (see Fig. 7.29), and it can be predicted that the absolute maximum value of T varies roughly as /x1/6. This dependence for the magnitude of T is weaker and in the opposite sense to the n 2 dependence for gyroscopic predissociations. The oscillation frequency of r(i ) versus E is also sensitive to the reduced mass. Since the phase difference, (f>(EVyj) [Eq. (7.6.10)] increases approximately in proportion to the area,... 

There axe several pitfalls to be avoided in formulating a predissociation mechanism. A linear variation of the linewidth with J(J +1) can be caused by either gyroscopic interaction or penetration through a centrifugal barrier. Another... 

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