Energy spectrum and g factors of alpha-Al2O3 : Ni2+ and their pressure-induced shifts

A unified calculation of the whole energy spectrum and g factors of the gro und state at normal pressure and their pressure-induced shifts for alpha-Al 2O3:Ni2+ has been carried out on the basis of the theory of pressure-induce d shifts and the diagonalization of the complete d(8) energy matrix adoptin g C-3 upsilon symmetry. The calculated results are in very good agreement w ith all the experimental data. The rates of change of all the levels with r espect to various parameters and the contributions to typical levels or spl ittings from various parameters have been calculated. The distinct differen ces of pressure-induced shifts of various levels are immediately determined by their characteristic dependencies on the parameters of interactions, an d the pressure-induced shifts (especially those of t(2)(6)e(2) E-1 (E) over cap) have provided important or crucial criteria for the correctness of th e calculation and assignment of the energy spectrum of alpha-Al2O3:Ni2+.