Monte Carlo Simulation ofEu3+-Doped BeF2Glass

Monte Carlo simulations of the structure of ${\mathrm{Eu}}^{3+}$-doped Be${\mathrm{F}}_2$ glass show that in contrast to the almost perfect fourfold coordination of Be by F, the rare-earth sites are disordered and no fixed coordination number can be defined. The calculated distribution of ${\mathrm{Eu}}^{3+}$ electronic energy levels is in general agreement with the inhomogeneous broadening observed in optical spectra and measured using laser-induced fluorescence line-narrowing techniques.