Ligand field stabilization energy 

The ligand field stabilization energy (LFSE) of an ion is measured through summing the orbital energies of the d electrons exist, measured comparative to the average energy of all five d levels. In octahedral coordination, every electron in a t₂g orbital is assigned an energy -(2/5)Δ_o, and every e_g electron an energy +(3/5)Δ_o. LFSE values in terms of Δ_o are

displayed for high- and low-spin configurations in Table 1. LFSE is 0 for ions with the d¹⁰ and high-spin d⁵ configurations in which all d orbitals are similarly occupied.

Greatest values of octahedral LFSE in high-spin states take place with the d³ and d⁸ configurations and for low-spin along with d⁶. These patterns of LFSE affect thermodynamic, structural and kinetic features of complex formation. They also have an influence on ionic radii and on lattice and solvation energies. Super imposed on a usual decrease of radius along with the 3d series, the ions with the largest LFSE contain smaller radii (and also larger lattice or solvation energies) than otherwise supposed. One interpretation of this influence is that in an ion with large LFSE, the repulsion among closed shells is decreased through the predominance of metal electrons in t₂g orbitals which do not point straight towards the ligands.