Absorption probability angular part

Here the proportionality factor fp ( J d J") 2/(2J +l) coincides with the dynamic part of the absorption probability introduced in Chapter 2. The sum in (5.10) presents the angular part of the absorption probability, whilst the factor (rmm + 0 %M ) 1 describes the effect upon /mm both on the part of perturbation by the external field, causing splitting of the magnetic sublevels j ujmm i and by spontaneous decay and collisions (anisotropic in the general case), together described by a set of relaxation rates Tmm Applying similar manipulations as for (5.7) to Eq. (5.6), we obtain an equation for fluorescence intensity ... 

In the case of the IR process, the dipole moment, p = p, is given by Equation 4.16 in the case of the Raman process, the dipole moment is given by p = aE. For molecules in the gas phase with a haphazard orientation and where the average of the square of the angular part is one, the probability for the absorption or emission of electromagnetic radiation per unit time for the dipole transition can be written as follows ... 

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