Orbitals and ligand fields

C represents a modified Curie constant deviating from the equation due to spin-orbit and ligand field effects. HS high spin LS low spin.4... 

Crystal field and ligand field molecular orbitals... 

Calculation of the Slater-Condon, spin-orbit coupling and ligand field parameters. The luminescence of CsMgBr3 Eu2+ is crucially dependent on the local coordination geometry of the Eu2+ dopant. Besides, a geometry change occurs in the excited state 4f 5d1 (see Table 2), leading to shifts... 

Table 3. Calculated Slater—Condon Integrals, Spin—Orbit Coupling Constants, and Ligand Field Parameters (in cm-1) for CsMgBr, Eu2+ Considering the Ground (GC) and Excited (EC) Configurations Local Structures of the Eu2+ Impurity...

The crystal and ligand field theories were developed to deal with only those properties of the complexes that are derived directly from the set of electrons originally occupying the d orbitals of the metal ion. Since these orbitals are the principal parents of the e and t2 MOs of the complex it is not unreasonable to treat the latter as though they were nothing more than split (crystal field theory) or split and somewhat diluted (ligand field theory) metal d orbitals. It is clear, however, that such a view can be only an approximation—indeed, a fairly ruthless one. Yet, with judicious empirical choice of one or more... 

Liehr, A. D., Molecular Orbital, Valence Bond, and Ligand Field, J. Chem. Educ. 39, 135 (1962). 

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