A simplified strong-field scheme and the absorption spectrum of Mn²⁺in rhodonite

Abstract

From the analysis of the observed absorption spectrum data it is supposed that the Mn2 ions in rhodonite, (Mn, Ca, Fe)SiO3, mainly occupy the two sites Oh and C4v. After considering the spin-orbit coupling and the vibronic coupling, the complete absorption spectrum of the Mn2+ in rhodonite has been calculated for the first time, by means of a simplified strong-field scheme advanced in this paper. It is shown from the good agreement between the theoretical and experimental values that this viewpoint is reasonable and the method is correct. However, the theory does not eliminate the possibility of alternative explanations such as Mn2+ ions at sites of O or D4, D4h and D2d symmetry.