A computer package has been developed to calculate the energy levels and the ligand field states for a full Hamiltonian including the electrostatic terms, Trees correction, the spin-orbit interaction and the ligand field interactions within the 3dᴺ configuration (N = 2 to 8). The program can deal with various cubic and non-cubic site symmetries of the 3d ion, namely the tetragonal, trigonal and orthorhombic ones. The package may be very useful in analyzing the EPR spectra of 3dᴺ ions and in correlating the ligand field parameters with spin Hamiltonian parameters derived from the orbital singlet states for some F-term (S = 1, 32) and S-term (S = 52) ions as well as the 3d⁴ and 3d⁶ ions with high-spin S = 2. Numerous examples of these ions in various crystals exist in the literature. Other spin states arising from strong ligand fields can also be dealt with. Copyright © 1992 Pergamon Press Ltd.