Resonance condition spin-orbit coupling

If eqn. (5) represented the resonance condition for all electrons, one would predict that they would all resonate at the same applied field for a given applied frequency. Consequently, the g factor would always be equal to that of the free electron. However, as well as possessing spin angular momentum, the unpaired electron also possesses electronic orbital angular momentum. The interaction between the two (via spin-orbit coupling) ensures that the electron has an effective magnetic moment different from that of the free electron. Hence, the resonance condition for an unpaired electron in a References pp. 349-352... 

In this paper we shall follow this line of reasoning, to show there are some symmetry conditions to be obeyed in order to represent the wavefunction of a molecule as a superposition of waveflinctions of resonance hybrids. Although some of the results to be presented may drastically differ from the classical VB picture, all the predictions are fiilly supported by calculations using modem VB methods, such as GVB (Generalized VB) and SCVB (Spin-Coupled VB), which consider explicit optimization of the singly-occupied orbitals, as suggested by Coulson and Fisher . 

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