Degeneracy, orbital level

The standard forms are listed for (i) E, Ti, and T2 states in a real orbital basis, (ii) Tj and T2 states in a complex orbital basis, and (iii) Ts levels arising from T12 orbital degeneracies r8 levels arising from E states retain the same Jahn-Teller activity as for that E state. 

In the general case there is degeneracy at the non-relativistic level, which is split by relativity. Then one must, after having performed the nonrel-ativistic calculation, extend the active space at orbital level by including all spin orbitals equivalent by symmetry. One then needs a matrix representation of the operator H2 in this basis to get the perturbation-adapted unperturbed states by diagonalizing this matrix representation. 

Introduction of the vibronic coupling (s / 0) causes removal of the above degeneracy and leads to the general vibronic-spin-orbit pattern presented in the central part of Figure 3. Each vibronic level is characterized by a particular K... 

The degeneracies of each of the levels can be calculated from the value of n, the allowed values of l and the total degeneracy of the /-orbitals ... 

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