The structure described by Cs2SnSe3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 5-coordinate geometry to two equivalent Se(1) and three equivalent Se(2) atoms. In the second Cs site, Cs(2) is bonded to two equivalent Se(2), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted CsSe7 pentagonal bipyramids that share corners with two equivalent Cs(2)Se7 pentagonal bipyramids, corners with three equivalent Sn(1)Se4 tetrahedra, edges with four equivalent Cs(2)Se7 pentagonal bipyramids, and edges with three equivalent Sn(1)Se4 tetrahedra. Sn(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form SnSe4 tetrahedra that share corners with three equivalent Cs(2)Se7 pentagonal bipyramids, edges with three equivalent Cs(2)Se7 pentagonal bipyramids, and  an edgeedge with one Sn(1)Se4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cs(1), three equivalent Cs(2), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing SeCs5Sn octahedra. The corner-sharing octahedral tilt angles range from 8-70°. In the second Se site, Se(2) is bonded to two equivalent Cs(2), three equivalent Cs(1), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing SeCs5Sn octahedra. The corner-sharing octahedral tilt angles range from 8-70°. In the third Se site, Se(3) is bonded in a 2-coordinate geometry to two equivalent Cs(2) and two equivalent Sn(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs2SnSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.582
_cell_length_b   8.346
_cell_length_c   9.669
_cell_angle_alpha   72.295
_cell_angle_beta   66.918
_cell_angle_gamma   62.987
_symmetry_Int_Tables_number   1
_cell_volume   495.515
_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
  Cs  Cs0  1  0.690  0.938  0.683  1.0
  Cs  Cs1  1  0.310  0.062  0.317  1.0
  Cs  Cs2  1  0.915  0.303  0.867  1.0
  Cs  Cs3  1  0.085  0.697  0.133  1.0
  Sn  Sn4  1  0.621  0.445  0.313  1.0
  Sn  Sn5  1  0.379  0.555  0.687  1.0
  Se  Se6  1  0.614  0.685  0.087  1.0
  Se  Se7  1  0.386  0.315  0.913  1.0
  Se  Se8  1  0.802  0.122  0.273  1.0
  Se  Se9  1  0.198  0.878  0.727  1.0
  Se  Se10  1  0.754  0.500  0.500  1.0
  Se  Se11  1  0.246  0.500  0.500  1.0
[/CIF]
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The structure described by Cs2SnSe3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 5-coordinate geometry to two equivalent Se(1) and three equivalent Se(2) atoms. In the second Cs site, Cs(2) is bonded to two equivalent Se(2), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted CsSe7 pentagonal bipyramids that share corners with two equivalent Cs(2)Se7 pentagonal bipyramids, corners with three equivalent Sn(1)Se4 tetrahedra, edges with four equivalent Cs(2)Se7 pentagonal bipyramids, and edges with three equivalent Sn(1)Se4 tetrahedra. Sn(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form SnSe4 tetrahedra that share corners with three equivalent Cs(2)Se7 pentagonal bipyramids, edges with three equivalent Cs(2)Se7 pentagonal bipyramids, and  an edgeedge with one Sn(1)Se4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cs(1), three equivalent Cs(2), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing SeCs5Sn octahedra. The corner-sharing octahedral tilt angles range from 8-70°. In the second Se site, Se(2) is bonded to two equivalent Cs(2), three equivalent Cs(1), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing SeCs5Sn octahedra. The corner-sharing octahedral tilt angles range from 8-70°. In the third Se site, Se(3) is bonded in a 2-coordinate geometry to two equivalent Cs(2) and two equivalent Sn(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs2SnSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.582
_cell_length_b   8.346
_cell_length_c   9.669
_cell_angle_alpha   72.295
_cell_angle_beta   66.918
_cell_angle_gamma   62.987
_symmetry_Int_Tables_number   1
_cell_volume   495.515
_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
  Cs  Cs0  1  0.690  0.938  0.683  1.0
  Cs  Cs1  1  0.310  0.062  0.317  1.0
  Cs  Cs2  1  0.915  0.303  0.867  1.0
  Cs  Cs3  1  0.085  0.697  0.133  1.0
  Sn  Sn4  1  0.621  0.445  0.313  1.0
  Sn  Sn5  1  0.379  0.555  0.687  1.0
  Se  Se6  1  0.614  0.685  0.087  1.0
  Se  Se7  1  0.386  0.315  0.913  1.0
  Se  Se8  1  0.802  0.122  0.273  1.0
  Se  Se9  1  0.198  0.878  0.727  1.0
  Se  Se10  1  0.754  0.500  0.500  1.0
  Se  Se11  1  0.246  0.500  0.500  1.0
[/CIF]
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