“…[36]). Lattice dimensions and the space group of topaz were first determined in [37], first full crystal structure determinations were published independently in 1928 in [38,39], with later refinements by several groups, using x-rays as well as neutron diffraction (see, e.g., [40][41][42][43][44][45][46]). These more recent detailed structural studies, in particular, include information about the topological configuration of the (OH) groups, which can occupy statistically the F sites of the crystal structure.…”