Crystal structures of the R3Mg0.5GeS7 (RÂ =Â Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds

The crystal structures of the R3Mg0.5GeS7 (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds (La3CuSiS7 structure type, space group P63, Pearson symbol hP23) were determined by means of X-ray powder diffraction: a = 0.9788(1) nm, c = 0.57745(5) nm, RBragg = 0.0814 (Y3Mg0.5GeS7); a = 1.0262(2) nm, c = 0.57849(7) nm, RBragg = 0.0687 (Ce3Mg0.5GeS7); a = 1.01249(3) nm, c = 0.58040(2) nm, RBragg = 0.0832 (Pr3Mg0.5GeS7); a = 1.00701(3) nm, c = 0.58047(3) nm, RBragg = 0.0636 (Nd3Mg0.5GeS7); a = 0.99500(3) nm, c = 0.57872(3) nm, RBragg = 0.0870 (Sm3Mg0.5GeS7); a = 0.99319(3) nm, c = 0.57083(3) nm, RBragg = 0.0901 (Gd3Mg0.5GeS7); a = 0.98007(5) nm, c = 0.57843(4) nm, RBragg = 0.0859 (Tb3Mg0.5GeS7); a = 0.97698(4) nm, c = 0.57675(5) nm, RBragg = 0.0931 (Dy3Mg0.5GeS7); a = 0.9735(2) nm, c = 0.57941(7) nm, RBragg = 0.0763 (Ho3Mg0.5GeS7); a = 0.9694(2) nm, c = 0.57994(7) nm, RBragg = 0.0724 (Er3Mg0.5GeS7). The R-centered trigonal prisms, Mg-centered octahedra and Ge-centered tetrahedra can be selected in the crystal structure of the R3Mg0.5GeS7 compounds.