Abstract
Complete trigonal ligand field, Coulombic repulsion, and spin–orbit interaction matrices have been computed for the d5 configuration. The ligand field potential for D3d, D3, C3v and a special case of C3 symmetry is expressed as a normalized spherical harmonic (NSH) potential. Ligand field energy level diagrams for the quartet states, as well as zero field (spin–orbit) splitting diagrams for the 6A1(S) ground state of a six-coordinate system, are presented. The advantages and limitations of the NSH formulation are discussed. The sign of the zero field parameter D is correlated with the sense of the trigonal distortion for six coordinate d5 systems of D3d symmetry, and two manganese(II) systems characterized by D3d symmetry are specifically considered.