Single crystal and far IR analysis of some lanthanide thiophosphates

The single crystal structures of GdPS₄ (1), DyPS₄ (2), and ErPS₄ (3) are reported. In addition, the far infrared (IR) spectrum of 3 and NdPS₄ (4) are reported. All three compounds crystallize in the tetragonal I4₁/acd space group. Unit cell dimensions are GdPS₄: a=10.709(7), b=10.709(7), and c=19.102(17) Å; DyPS₄: a=10.7305(11), b=10.7305(11), and c=19.111(3) Å; ErPS₄: a=10.611(5), b=10.611(5), and c=18.947(13) Å. Far IR spectra are consistent with slightly distorted tetrahedra for the PS₄^-3 anions. The compounds reported here are isomorphous to several other lanthanide thiophosphates.