In Part I (Chapter 3 in this volume - Wilder et al., 2004) we described the basic principles of crystal field theory (CFT) based on group theory and symmetry. The usefulness of CFT resides in the fact that it can predict the type and number of electronic transitions and their relative energies for transition metal ions in crystals. Hence CFT enables interpretation of the optical absorption spectra. The crystal (or ligand) field induced on the central ion depends on the type and positions of the ligands (i.e., bond angles and distances R) and on the point symmetry of the resulting coordination polyhedron. The number of exited crystal field (CF) states and the type of the ground state arising from a given free-ion d^N configuration depends solely upon molecular symmetry, i.e. the site symmetry in case of crystals, and is independent of any model used to describe the metal-ligand bonds. Although the exact energies cannot be calculated ab initio, it is possible to extract empirical parameters from experimental electronic absorption spectra which describe the interaction between metal and ligand. For a given d^NX₆ complex with an ideal octahedral coordination (symmetry O_h), the cubic CF splitting parameter 10Dq, together with Racah parameters B and C, provide basis for a reasonably complete description of the electronic spectra (Lever, 1984). In most crystals the site symmetry is, however, lower than O_h. This requires introduction of additional, so-called distortion parameters to describe the lower symmetry CF components