Magnetic circular dichroism and moments for A2 → E transition in C3ν defect centers

The spectral line shape of the magnetic circular dichroism (MCD) for the A2 → E transition is investigated. The dynamic Jahn–Teller effect is taken into account by two different methods, i.e. (i) in Franck–Condon and adiabatic approximation and (ii) method of moments. The line-shape function for the magnetic circular dichroism is calculated without using the rigid shift approximation. A comparison of this line shape with the one obtained in the rigid shift shows the two line shapes to be different. General closed expression for the nth order moment is obtained, in the absence and the presence of an externally applied magnetic field, by making use of (i). Zeroth-, first-, and second-order and the change in the third-order moments have been obtained using (ii). The moments up to the second order and the change in the third-order moment have the same expressions as obtained by (i) and (ii). The MCD line shape and the different order moments have also been obtained for the 3A2 → 3E electronic transition in the R′ center.