Abstract: The local structure,optical spectra,electron paramagnetic resonance(EPR) spectra and susceptibility of NiSO₄·6H₂O crystal at room temperature are calculated with a semi-SCF d-orbit wave function model for free Ni²⁺ ions,a point-charge model and Ballhausen's SCF wave functions for O^2- using a complete diagonalization procedure(CDP).Theoretical results are in good agreement with experimental data.Some controversial issues,such as perturbation method,LCAO-MO method,parameter fitting and Clementi's single-zeta wave function are explained.

Key words: crystal and ligand fields, optical and magnetic properties, electron paramagnetic resonance spectra, local structure, susceptibility