Crystal structures of the R2Pb3Sn3S12 (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds

The crystal structures of the R2Pb3Sn3S12 (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds (space group Pmc21, Pearson symbol oP40, a = 0.38992 (1) nm, b = 2.01175 (7) nm, c = 1.15140 (4) nm, RI = 0.0785 for Ho2Pb3Sn3S12) were investigated using X-ray powder diffraction. The R1 atoms are surrounded by trigonal prisms with two additional atoms, the R2 atoms by distorted octahedra with one additional atom. The Pb1 and Pb3 atoms are surrounded by trigonal prisms with one additional atom, the Pb2 atoms by trigonal prisms with two additional atoms. Octahedral surrounding exists for Sn1 and Sn2. The Sn3 atoms are located in trigonal bipyramids. Four or five neighbours surround the S atoms.