%0 Journal Article
%T Effective-Hamiltonian parameters for \emph{ab initio} energy-level calculations of SrCl$_{2}$:Yb$^{2+}$ and CsCaBr$_{3}$:Yb$^{2+}$
%A A. J. Salkeld
%A M. F. Reid
%A J. -P. R. Wells
%A G. Sanchez-Sanz
%A L. Seijo
%A Z. Barandiaran
%J Physics
%D 2013
%I arXiv
%R 10.1088/0953-8984/25/41/415504
%X Calculated energy levels from recent \emph{ab initio} studies of the electronic structure of SrCl$_{2}$:Yb$^{2+}$ and CsCaBr$_{3}$:Yb$^{2+}$ are fitted with a semi-empirical "crystal-field" Hamiltonian, which acts within the model space $4f^{14} + 4f^{13}5d + 4f^{13}6s$. Parameters are obtained for the minima of the potential-energy curves for each energy level and also for a range of anion-cation separations. The parameters are compared with published results parameters fitted to experimental data and to atomic calculations. The states with significant $4f^{13}6s$ character give a good approximation of the impurity-trapped exciton states that appear in the \emph{ab initio} calculations.
%U http://arxiv.org/abs/1307.5953v2