High-Field Zeeman Anisotropy Fluorescence: Low-$J$ Transitions of $C_{4v}$, $C_s$, and $C_{2v}{\mathrm{Sm}}^{2^{+}}$ Sites in KCl

At 93.5 kG, all 23 observed 4.2K fluorescence lines arising from the ${}_{}{}^5{}_{}{}^{}D_0^{}{}_{}{}^{}\to {}_{}{}^7{}_{}{}^{}F_0^{}{}_{}{}^{}$, ${}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$, and ${}_{}{}^7{}_{}{}^{}F_2^{}{}_{}{}^{}$ transitions in KCl:${\mathrm{Sm}}^{2+}$ show Zeeman effects, 11 of which give rise to Zeeman anisotropy fluorescence patterns. Contrary to the current postulate of a single complex model, it is shown that the fluorescence from these transitions actually arises from a mixture of (in the order of decreasing importance) ${\mathrm{C}}_{4v}$, ${\mathrm{C}}_s$, and ${\mathrm{C}}_{2v}$ sites. This finding lends strong support to the equilibrium distrubution theory of the ${\mathrm{Sm}}^{2+}$ -${\mathrm{K}}^{+}$ vacancy pairs.