A theoretical method for investigating the inter-relation between the electronic and molecular structures of 3d3 configuration ions in a tetragonal ligand field is established on the basis of the 120 × 120 complete energy matrices.Using this method, the local structure parameters of two tetragonal Cr3+ centers in the NH4 Cl:Cr3+ system are determined. Furthermore, the relations between the molecular symmetry and the ligand field symmetry are discussed.