Extending Phenomenological Crystal-Field Methods to $C_1$ Point-Group Symmetry: Characterization of the Optically-Excited Hyperfine Structure of ${}^{167}$Er${}^{3+}$:Y${}_2$SiO${}_5$

Sebastian P. Horvath, Jelena V. Rakonjac, Yu-Hui Chen +4

We show that crystal-field calculations for $C_1$ point-group symmetry are possible, and that such calculations can be performed with sufficient accuracy to have substantial utilit…