The material structure described by Er2Sn3(PbS4)3 crystallizes in the orthorhombic Pmc2_1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 8-coordinate geometry to one S(4), one S(8), two equivalent S(11), two equivalent S(2), and two equivalent S(3) atoms. In the second Er site, Er(2) is bonded to one S(5), one S(6), one S(7), two equivalent S(1), and two equivalent S(10) atoms to form distorted ErS7 pentagonal bipyramids that share corners with two equivalent Sn(2)S6 octahedra, edges with two equivalent Sn(1)S6 octahedra, edges with two equivalent Sn(2)S6 octahedra, and edges with two equivalent Er(2)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are three inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 6-coordinate geometry to one S(4), one S(6), two equivalent S(11), and two equivalent S(9) atoms. In the second Pb site, Pb(2) is bonded in a 7-coordinate geometry to one S(7), two equivalent S(1), two equivalent S(10), and two equivalent S(9) atoms. In the third Pb site, Pb(3) is bonded in a 3-coordinate geometry to one S(5) and two equivalent S(12) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(1), one S(2), two equivalent S(4), and two equivalent S(5) atoms to form SnS6 octahedra that share edges with two equivalent Sn(1)S6 octahedra and edges with two equivalent Er(2)S7 pentagonal bipyramids. In the second Sn site, Sn(2) is bonded to one S(10), one S(9), two equivalent S(6), and two equivalent S(7) atoms to form SnS6 octahedra that share corners with two equivalent Er(2)S7 pentagonal bipyramids, edges with two equivalent Sn(2)S6 octahedra, and edges with two equivalent Er(2)S7 pentagonal bipyramids. In the third Sn site, Sn(3) is bonded to one S(11), one S(12), one S(3), and two equivalent S(8) atoms to form corner-sharing SnS5 trigonal bipyramids. There are twelve inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Er(2), two equivalent Pb(2), and one Sn(1) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one Sn(1) atom. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Sn(3) atom. In the fourth S site, S(4) is bonded to one Er(1), one Pb(1), and two equivalent Sn(1) atoms to form distorted SErSn2Pb trigonal pyramids that share corners with two equivalent S(9)SnPb4 square pyramids, corners with two equivalent S(4)ErSn2Pb trigonal pyramids, corners with two equivalent S(5)ErSn2Pb trigonal pyramids, and  an edgeedge with one S(5)ErSn2Pb trigonal pyramid. In the fifth S site, S(5) is bonded to one Er(2), one Pb(3), and two equivalent Sn(1) atoms to form a mixture of distorted corner and edge-sharing SErSn2Pb trigonal pyramids. In the sixth S site, S(6) is bonded in a distorted see-saw-like geometry to one Er(2), one Pb(1), and two equivalent Sn(2) atoms. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one Er(2), one Pb(2), and two equivalent Sn(2) atoms. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one Er(1) and two equivalent Sn(3) atoms. In the ninth S site, S(9) is bonded to two equivalent Pb(1), two equivalent Pb(2), and one Sn(2) atom to form distorted SSnPb4 square pyramids that share corners with two equivalent S(4)ErSn2Pb trigonal pyramids and edges with two equivalent S(9)SnPb4 square pyramids. In the tenth S site, S(10) is bonded in a 5-coordinate geometry to two equivalent Er(2), two equivalent Pb(2), and one Sn(2) atom. In the eleventh S site, S(11) is bonded in a 5-coordinate geometry to two equivalent Er(1), two equivalent Pb(1), and one Sn(3) atom. In the twelfth S site, S(12) is bonded in a distorted single-bond geometry to two equivalent Pb(3) and one Sn(3) atom. is represented by the CIF file [CIF]
data_Er2Sn3(PbS4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.945
_cell_length_b   11.631
_cell_length_c   20.345
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   933.426
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Er  Er0  1  0.500  0.650  0.412  1.0
  Er  Er1  1  0.500  0.150  0.588  1.0
  Er  Er2  1  0.500  0.825  0.895  1.0
  Er  Er3  1  0.500  0.325  0.105  1.0
  Sn  Sn4  1  0.000  0.001  0.751  1.0
  Sn  Sn5  1  0.000  0.501  0.249  1.0
  Sn  Sn6  1  0.000  0.519  0.912  1.0
  Sn  Sn7  1  0.000  0.019  0.088  1.0
  Sn  Sn8  1  0.000  0.994  0.425  1.0
  Sn  Sn9  1  0.000  0.494  0.575  1.0
  Pb  Pb10  1  0.500  0.404  0.742  1.0
  Pb  Pb11  1  0.500  0.904  0.258  1.0
  Pb  Pb12  1  0.500  0.197  0.914  1.0
  Pb  Pb13  1  0.500  0.697  0.086  1.0
  Pb  Pb14  1  0.500  0.771  0.622  1.0
  Pb  Pb15  1  0.500  0.271  0.378  1.0
  S  S16  1  0.000  0.989  0.876  1.0
  S  S17  1  0.000  0.489  0.124  1.0
  S  S18  1  0.000  0.987  0.626  1.0
  S  S19  1  0.000  0.487  0.374  1.0
  S  S20  1  0.000  0.683  0.509  1.0
  S  S21  1  0.000  0.183  0.491  1.0
  S  S22  1  0.500  0.646  0.258  1.0
  S  S23  1  0.500  0.146  0.742  1.0
  S  S24  1  0.500  0.849  0.758  1.0
  S  S25  1  0.500  0.349  0.242  1.0
  S  S26  1  0.500  0.602  0.842  1.0
  S  S27  1  0.500  0.102  0.158  1.0
  S  S28  1  0.500  0.440  0.984  1.0
  S  S29  1  0.500  0.940  0.016  1.0
  S  S30  1  0.500  0.936  0.490  1.0
  S  S31  1  0.500  0.436  0.510  1.0
  S  S32  1  0.000  0.337  0.843  1.0
  S  S33  1  0.000  0.837  0.157  1.0
  S  S34  1  0.000  0.715  0.968  1.0
  S  S35  1  0.000  0.215  0.032  1.0
  S  S36  1  0.000  0.803  0.359  1.0
  S  S37  1  0.000  0.303  0.641  1.0
  S  S38  1  0.000  0.602  0.679  1.0
  S  S39  1  0.000  0.102  0.321  1.0
[/CIF]
.
The material structure described by Er2Sn3(PbS4)3 crystallizes in the orthorhombic Pmc2_1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 8-coordinate geometry to one S(4), one S(8), two equivalent S(11), two equivalent S(2), and two equivalent S(3) atoms. In the second Er site, Er(2) is bonded to one S(5), one S(6), one S(7), two equivalent S(1), and two equivalent S(10) atoms to form distorted ErS7 pentagonal bipyramids that share corners with two equivalent Sn(2)S6 octahedra, edges with two equivalent Sn(1)S6 octahedra, edges with two equivalent Sn(2)S6 octahedra, and edges with two equivalent Er(2)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are three inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 6-coordinate geometry to one S(4), one S(6), two equivalent S(11), and two equivalent S(9) atoms. In the second Pb site, Pb(2) is bonded in a 7-coordinate geometry to one S(7), two equivalent S(1), two equivalent S(10), and two equivalent S(9) atoms. In the third Pb site, Pb(3) is bonded in a 3-coordinate geometry to one S(5) and two equivalent S(12) atoms. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(1), one S(2), two equivalent S(4), and two equivalent S(5) atoms to form SnS6 octahedra that share edges with two equivalent Sn(1)S6 octahedra and edges with two equivalent Er(2)S7 pentagonal bipyramids. In the second Sn site, Sn(2) is bonded to one S(10), one S(9), two equivalent S(6), and two equivalent S(7) atoms to form SnS6 octahedra that share corners with two equivalent Er(2)S7 pentagonal bipyramids, edges with two equivalent Sn(2)S6 octahedra, and edges with two equivalent Er(2)S7 pentagonal bipyramids. In the third Sn site, Sn(3) is bonded to one S(11), one S(12), one S(3), and two equivalent S(8) atoms to form corner-sharing SnS5 trigonal bipyramids. There are twelve inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Er(2), two equivalent Pb(2), and one Sn(1) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one Sn(1) atom. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Sn(3) atom. In the fourth S site, S(4) is bonded to one Er(1), one Pb(1), and two equivalent Sn(1) atoms to form distorted SErSn2Pb trigonal pyramids that share corners with two equivalent S(9)SnPb4 square pyramids, corners with two equivalent S(4)ErSn2Pb trigonal pyramids, corners with two equivalent S(5)ErSn2Pb trigonal pyramids, and  an edgeedge with one S(5)ErSn2Pb trigonal pyramid. In the fifth S site, S(5) is bonded to one Er(2), one Pb(3), and two equivalent Sn(1) atoms to form a mixture of distorted corner and edge-sharing SErSn2Pb trigonal pyramids. In the sixth S site, S(6) is bonded in a distorted see-saw-like geometry to one Er(2), one Pb(1), and two equivalent Sn(2) atoms. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one Er(2), one Pb(2), and two equivalent Sn(2) atoms. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one Er(1) and two equivalent Sn(3) atoms. In the ninth S site, S(9) is bonded to two equivalent Pb(1), two equivalent Pb(2), and one Sn(2) atom to form distorted SSnPb4 square pyramids that share corners with two equivalent S(4)ErSn2Pb trigonal pyramids and edges with two equivalent S(9)SnPb4 square pyramids. In the tenth S site, S(10) is bonded in a 5-coordinate geometry to two equivalent Er(2), two equivalent Pb(2), and one Sn(2) atom. In the eleventh S site, S(11) is bonded in a 5-coordinate geometry to two equivalent Er(1), two equivalent Pb(1), and one Sn(3) atom. In the twelfth S site, S(12) is bonded in a distorted single-bond geometry to two equivalent Pb(3) and one Sn(3) atom. is represented by the CIF file [CIF]
data_Er2Sn3(PbS4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.945
_cell_length_b   11.631
_cell_length_c   20.345
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   933.426
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Er  Er0  1  0.500  0.650  0.412  1.0
  Er  Er1  1  0.500  0.150  0.588  1.0
  Er  Er2  1  0.500  0.825  0.895  1.0
  Er  Er3  1  0.500  0.325  0.105  1.0
  Sn  Sn4  1  0.000  0.001  0.751  1.0
  Sn  Sn5  1  0.000  0.501  0.249  1.0
  Sn  Sn6  1  0.000  0.519  0.912  1.0
  Sn  Sn7  1  0.000  0.019  0.088  1.0
  Sn  Sn8  1  0.000  0.994  0.425  1.0
  Sn  Sn9  1  0.000  0.494  0.575  1.0
  Pb  Pb10  1  0.500  0.404  0.742  1.0
  Pb  Pb11  1  0.500  0.904  0.258  1.0
  Pb  Pb12  1  0.500  0.197  0.914  1.0
  Pb  Pb13  1  0.500  0.697  0.086  1.0
  Pb  Pb14  1  0.500  0.771  0.622  1.0
  Pb  Pb15  1  0.500  0.271  0.378  1.0
  S  S16  1  0.000  0.989  0.876  1.0
  S  S17  1  0.000  0.489  0.124  1.0
  S  S18  1  0.000  0.987  0.626  1.0
  S  S19  1  0.000  0.487  0.374  1.0
  S  S20  1  0.000  0.683  0.509  1.0
  S  S21  1  0.000  0.183  0.491  1.0
  S  S22  1  0.500  0.646  0.258  1.0
  S  S23  1  0.500  0.146  0.742  1.0
  S  S24  1  0.500  0.849  0.758  1.0
  S  S25  1  0.500  0.349  0.242  1.0
  S  S26  1  0.500  0.602  0.842  1.0
  S  S27  1  0.500  0.102  0.158  1.0
  S  S28  1  0.500  0.440  0.984  1.0
  S  S29  1  0.500  0.940  0.016  1.0
  S  S30  1  0.500  0.936  0.490  1.0
  S  S31  1  0.500  0.436  0.510  1.0
  S  S32  1  0.000  0.337  0.843  1.0
  S  S33  1  0.000  0.837  0.157  1.0
  S  S34  1  0.000  0.715  0.968  1.0
  S  S35  1  0.000  0.215  0.032  1.0
  S  S36  1  0.000  0.803  0.359  1.0
  S  S37  1  0.000  0.303  0.641  1.0
  S  S38  1  0.000  0.602  0.679  1.0
  S  S39  1  0.000  0.102  0.321  1.0
[/CIF]
.