Optical spectrum and local lattice structure for ruby

By diagonalizing the 120×120 complete energy matrices for d<Superscript>3</Superscript> ion in trigonal crystal field, which contains the electrostatic interaction, the trigonal field as well as the spin-orbit interaction, the unified calculation of the whole optical and EPR spectra for ruby are made. And matrix elements of the Zeeman energy with the magnetic field parallel or perpendicular to the trigonal axis are introduced into the complete energy matrices for obtaining the g factors of the energy levels. It is concluded that zero-field splitting and optical spectra as well as g factors are in good agreement with the experimental data and the distorted local lattice structure is determined firstly results from a stretching of the O<Superscript>2-</Superscript> ions along the C<Subscript>3</Subscript> axis. The pressure-induced shifts of energy levels, g factors and local lattice structure are also discussed. In particular, all the calculations are carried out successfully within the framework of the crystal-field model which is consistent with the opinion of Macfarlane and Sturge that if all terms within the d<Superscript>3</Superscript> configuration are included, one need not go outside conventional crystal-field theory. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007