Ab initio Calculation of the charge distribution and the ligand field splitting in the tetrahedral halo complexes CuCl 4 2− 4 and NiCl 4 2−

The charge distribution and the ligand field splitting in the tetrachloro complexes CuCl₄^2–and NiCl₄^2–have been investigated by means of the restricted Hartree-Fock method. A rather large basis set of contracted Gaussian type orbitals has been employed. The charge distributions have been analysed by means of Mulliken population analyses. The ligand field splitting 10Dq has been compared with literature results known for the octahedral cluster NiF₆^4–occurring in KNiF₃. A detailed analysis has been carried out for CuCl₄^2–. From calculations on a selected number of states of NiCl₄^2–the Racah parameters B and C have been obtained.