Spin-orbit coupling through-bond

Figure 4.25. Sum-over-atoms factor in the spin-orbit coupling vector // a) in orthogonally twisted ethylene and b) in (0, 90°) twisted trimethylene biradical, using Equation (4.12) and (4.13) most localized orbitals x - Xh and nonvanishing atomic vectorial contributions from Xh (white through-space, black through-bond).

LFT is a parametric approach in which the symmetry of the complex is treated explicitly but the bonding is handled implicitly through the ligand field parameters. These parameters describe the three contributions to the overall Hamiltonian, FI the ligand field, Hup, interelectronic repulsion, Z/ er and spin orbit coupling, Hps- The relative importance of each of these terms depends on the element s position in the periodic table. 

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