Optimization of first-principles calculation conditions for multiplet energies of Fe3 + and Co3 + in α-Al2O3

Abstract

Corundum can contain various transition metals as impurities, for example, ruby. Ruby is used as solid state laser. The prediction of the electronic state of these transition metals is very important for the development of novel optical materials. The CI calculation used finite Slater determinants, the calculated mutiplet energies is overestimated generally. In this study, we optimized the calculation multiplet energy of transition metals in α-Al2O3 by considering some corrections.