The crystal structure described by Ca3Sn2S7 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Ima2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent S(5), two equivalent S(6), two equivalent S(7), and two equivalent S(8) atoms. In the second Ca site, Ca(2) is bonded to one S(2), one S(3), two equivalent S(1), and two equivalent S(4) atoms to form CaS6 octahedra that share corners with four equivalent Ca(3)S6 octahedra, corners with four equivalent Ca(4)S6 octahedra, corners with two equivalent Sn(1)S4 tetrahedra, corners with two equivalent Sn(2)S4 trigonal pyramids, edges with two equivalent Ca(3)S6 octahedra, and  an edgeedge with one Sn(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-55°. In the third Ca site, Ca(3) is bonded to one S(1), one S(2), one S(3), one S(4), one S(5), and one S(7) atom to form CaS6 octahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  a cornercorner with one Sn(1)S4 tetrahedra,  a cornercorner with one Sn(2)S4 trigonal pyramid,  an edgeedge with one Ca(2)S6 octahedra,  an edgeedge with one Ca(3)S6 octahedra,  an edgeedge with one Ca(4)S6 octahedra,  an edgeedge with one Sn(1)S4 tetrahedra, and  an edgeedge with one Sn(2)S4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 54-62°. In the fourth Ca site, Ca(4) is bonded to one S(1), one S(4), one S(5), one S(6), one S(7), and one S(8) atom to form CaS6 octahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(3)S6 octahedra,  a cornercorner with one Sn(1)S4 tetrahedra, corners with two equivalent Sn(3)S4 tetrahedra, corners with two equivalent Sn(2)S4 trigonal pyramids,  an edgeedge with one Ca(3)S6 octahedra, and  an edgeedge with one Sn(2)S4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 49-62°. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form SnS4 tetrahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(3)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  an edgeedge with one Ca(2)S6 octahedra, and edges with two equivalent Ca(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. In the second Sn site, Sn(2) is bonded to one S(4), one S(5), one S(6), and one S(7) atom to form distorted SnS4 trigonal pyramids that share  a cornercorner with one Ca(2)S6 octahedra,  a cornercorner with one Ca(3)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  a cornercorner with one Sn(3)S4 tetrahedra,  an edgeedge with one Ca(3)S6 octahedra, and  an edgeedge with one Ca(4)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-72°. In the third Sn site, Sn(3) is bonded to two equivalent S(6) and two equivalent S(8) atoms to form SnS4 tetrahedra that share corners with four equivalent Ca(4)S6 octahedra and corners with two equivalent Sn(2)S4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 63-71°. There are eight inequivalent S sites. In the first S site, S(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(4), and one Sn(3) atom. In the second S site, S(6) is bonded to one Ca(1), one Ca(4), one Sn(2), and one Sn(3) atom to form distorted SCa2Sn2 trigonal pyramids that share corners with two equivalent S(7)Ca3Sn tetrahedra, corners with two equivalent S(6)Ca2Sn2 trigonal pyramids, and  an edgeedge with one S(7)Ca3Sn tetrahedra. In the third S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ca(4), and one Sn(1) atom. In the fourth S site, S(2) is bonded in a rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(3), and one Sn(1) atom. In the fifth S site, S(3) is bonded to one Ca(2), two equivalent Ca(3), and one Sn(1) atom to form corner-sharing SCa3Sn tetrahedra. In the sixth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ca(4), and one Sn(2) atom. In the seventh S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Ca(4), and one Sn(2) atom. In the eighth S site, S(7) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Sn(2) atom to form distorted SCa3Sn tetrahedra that share  a cornercorner with one S(3)Ca3Sn tetrahedra,  a cornercorner with one S(7)Ca3Sn tetrahedra, corners with two equivalent S(6)Ca2Sn2 trigonal pyramids, and  an edgeedge with one S(6)Ca2Sn2 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Sn2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.517
_cell_length_b   14.425
_cell_length_c   16.009
_cell_angle_alpha   116.778
_cell_angle_beta   101.745
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1308.331
_cell_formula_units_Z   4
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
  Ca  Ca0  1  0.500  0.507  0.000  1.0
  Ca  Ca1  1  0.000  0.007  0.000  1.0
  Ca  Ca2  1  0.258  0.974  0.500  1.0
  Ca  Ca3  1  0.742  0.474  0.500  1.0
  Ca  Ca4  1  0.333  0.322  0.658  1.0
  Ca  Ca5  1  0.667  0.663  0.342  1.0
  Ca  Ca6  1  0.174  0.163  0.342  1.0
  Ca  Ca7  1  0.826  0.822  0.658  1.0
  Ca  Ca8  1  0.894  0.167  0.786  1.0
  Ca  Ca9  1  0.106  0.380  0.214  1.0
  Ca  Ca10  1  0.608  0.880  0.214  1.0
  Ca  Ca11  1  0.392  0.667  0.786  1.0
  Sn  Sn12  1  0.677  0.156  0.500  1.0
  Sn  Sn13  1  0.323  0.656  0.500  1.0
  Sn  Sn14  1  0.332  0.979  0.788  1.0
  Sn  Sn15  1  0.668  0.191  0.212  1.0
  Sn  Sn16  1  0.044  0.691  0.212  1.0
  Sn  Sn17  1  0.956  0.479  0.788  1.0
  Sn  Sn18  1  0.500  0.266  0.000  1.0
  Sn  Sn19  1  0.000  0.766  0.000  1.0
  S  S20  1  0.574  0.146  0.633  1.0
  S  S21  1  0.426  0.513  0.367  1.0
  S  S22  1  0.440  0.013  0.367  1.0
  S  S23  1  0.560  0.646  0.633  1.0
  S  S24  1  0.508  0.306  0.500  1.0
  S  S25  1  0.492  0.806  0.500  1.0
  S  S26  1  0.043  0.152  0.500  1.0
  S  S27  1  0.957  0.652  0.500  1.0
  S  S28  1  0.088  0.988  0.657  1.0
  S  S29  1  0.912  0.331  0.343  1.0
  S  S30  1  0.931  0.831  0.343  1.0
  S  S31  1  0.069  0.488  0.657  1.0
  S  S32  1  0.140  0.344  0.809  1.0
  S  S33  1  0.860  0.535  0.191  1.0
  S  S34  1  0.830  0.035  0.191  1.0
  S  S35  1  0.170  0.844  0.809  1.0
  S  S36  1  0.210  0.125  0.921  1.0
  S  S37  1  0.790  0.203  0.079  1.0
  S  S38  1  0.788  0.703  0.079  1.0
  S  S39  1  0.212  0.625  0.921  1.0
  S  S40  1  0.704  0.002  0.810  1.0
  S  S41  1  0.296  0.191  0.190  1.0
  S  S42  1  0.393  0.691  0.190  1.0
  S  S43  1  0.607  0.502  0.810  1.0
  S  S44  1  0.658  0.314  0.903  1.0
  S  S45  1  0.342  0.411  0.097  1.0
  S  S46  1  0.255  0.911  0.097  1.0
  S  S47  1  0.745  0.814  0.903  1.0
[/CIF]
.
The crystal structure described by Ca3Sn2S7 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Ima2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent S(5), two equivalent S(6), two equivalent S(7), and two equivalent S(8) atoms. In the second Ca site, Ca(2) is bonded to one S(2), one S(3), two equivalent S(1), and two equivalent S(4) atoms to form CaS6 octahedra that share corners with four equivalent Ca(3)S6 octahedra, corners with four equivalent Ca(4)S6 octahedra, corners with two equivalent Sn(1)S4 tetrahedra, corners with two equivalent Sn(2)S4 trigonal pyramids, edges with two equivalent Ca(3)S6 octahedra, and  an edgeedge with one Sn(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-55°. In the third Ca site, Ca(3) is bonded to one S(1), one S(2), one S(3), one S(4), one S(5), and one S(7) atom to form CaS6 octahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  a cornercorner with one Sn(1)S4 tetrahedra,  a cornercorner with one Sn(2)S4 trigonal pyramid,  an edgeedge with one Ca(2)S6 octahedra,  an edgeedge with one Ca(3)S6 octahedra,  an edgeedge with one Ca(4)S6 octahedra,  an edgeedge with one Sn(1)S4 tetrahedra, and  an edgeedge with one Sn(2)S4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 54-62°. In the fourth Ca site, Ca(4) is bonded to one S(1), one S(4), one S(5), one S(6), one S(7), and one S(8) atom to form CaS6 octahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(3)S6 octahedra,  a cornercorner with one Sn(1)S4 tetrahedra, corners with two equivalent Sn(3)S4 tetrahedra, corners with two equivalent Sn(2)S4 trigonal pyramids,  an edgeedge with one Ca(3)S6 octahedra, and  an edgeedge with one Sn(2)S4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 49-62°. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form SnS4 tetrahedra that share corners with two equivalent Ca(2)S6 octahedra, corners with two equivalent Ca(3)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  an edgeedge with one Ca(2)S6 octahedra, and edges with two equivalent Ca(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. In the second Sn site, Sn(2) is bonded to one S(4), one S(5), one S(6), and one S(7) atom to form distorted SnS4 trigonal pyramids that share  a cornercorner with one Ca(2)S6 octahedra,  a cornercorner with one Ca(3)S6 octahedra, corners with two equivalent Ca(4)S6 octahedra,  a cornercorner with one Sn(3)S4 tetrahedra,  an edgeedge with one Ca(3)S6 octahedra, and  an edgeedge with one Ca(4)S6 octahedra. The corner-sharing octahedral tilt angles range from 60-72°. In the third Sn site, Sn(3) is bonded to two equivalent S(6) and two equivalent S(8) atoms to form SnS4 tetrahedra that share corners with four equivalent Ca(4)S6 octahedra and corners with two equivalent Sn(2)S4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 63-71°. There are eight inequivalent S sites. In the first S site, S(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(4), and one Sn(3) atom. In the second S site, S(6) is bonded to one Ca(1), one Ca(4), one Sn(2), and one Sn(3) atom to form distorted SCa2Sn2 trigonal pyramids that share corners with two equivalent S(7)Ca3Sn tetrahedra, corners with two equivalent S(6)Ca2Sn2 trigonal pyramids, and  an edgeedge with one S(7)Ca3Sn tetrahedra. In the third S site, S(1) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ca(4), and one Sn(1) atom. In the fourth S site, S(2) is bonded in a rectangular see-saw-like geometry to one Ca(2), two equivalent Ca(3), and one Sn(1) atom. In the fifth S site, S(3) is bonded to one Ca(2), two equivalent Ca(3), and one Sn(1) atom to form corner-sharing SCa3Sn tetrahedra. In the sixth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ca(4), and one Sn(2) atom. In the seventh S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Ca(4), and one Sn(2) atom. In the eighth S site, S(7) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Sn(2) atom to form distorted SCa3Sn tetrahedra that share  a cornercorner with one S(3)Ca3Sn tetrahedra,  a cornercorner with one S(7)Ca3Sn tetrahedra, corners with two equivalent S(6)Ca2Sn2 trigonal pyramids, and  an edgeedge with one S(6)Ca2Sn2 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Sn2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.517
_cell_length_b   14.425
_cell_length_c   16.009
_cell_angle_alpha   116.778
_cell_angle_beta   101.745
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1308.331
_cell_formula_units_Z   4
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
  Ca  Ca0  1  0.500  0.507  0.000  1.0
  Ca  Ca1  1  0.000  0.007  0.000  1.0
  Ca  Ca2  1  0.258  0.974  0.500  1.0
  Ca  Ca3  1  0.742  0.474  0.500  1.0
  Ca  Ca4  1  0.333  0.322  0.658  1.0
  Ca  Ca5  1  0.667  0.663  0.342  1.0
  Ca  Ca6  1  0.174  0.163  0.342  1.0
  Ca  Ca7  1  0.826  0.822  0.658  1.0
  Ca  Ca8  1  0.894  0.167  0.786  1.0
  Ca  Ca9  1  0.106  0.380  0.214  1.0
  Ca  Ca10  1  0.608  0.880  0.214  1.0
  Ca  Ca11  1  0.392  0.667  0.786  1.0
  Sn  Sn12  1  0.677  0.156  0.500  1.0
  Sn  Sn13  1  0.323  0.656  0.500  1.0
  Sn  Sn14  1  0.332  0.979  0.788  1.0
  Sn  Sn15  1  0.668  0.191  0.212  1.0
  Sn  Sn16  1  0.044  0.691  0.212  1.0
  Sn  Sn17  1  0.956  0.479  0.788  1.0
  Sn  Sn18  1  0.500  0.266  0.000  1.0
  Sn  Sn19  1  0.000  0.766  0.000  1.0
  S  S20  1  0.574  0.146  0.633  1.0
  S  S21  1  0.426  0.513  0.367  1.0
  S  S22  1  0.440  0.013  0.367  1.0
  S  S23  1  0.560  0.646  0.633  1.0
  S  S24  1  0.508  0.306  0.500  1.0
  S  S25  1  0.492  0.806  0.500  1.0
  S  S26  1  0.043  0.152  0.500  1.0
  S  S27  1  0.957  0.652  0.500  1.0
  S  S28  1  0.088  0.988  0.657  1.0
  S  S29  1  0.912  0.331  0.343  1.0
  S  S30  1  0.931  0.831  0.343  1.0
  S  S31  1  0.069  0.488  0.657  1.0
  S  S32  1  0.140  0.344  0.809  1.0
  S  S33  1  0.860  0.535  0.191  1.0
  S  S34  1  0.830  0.035  0.191  1.0
  S  S35  1  0.170  0.844  0.809  1.0
  S  S36  1  0.210  0.125  0.921  1.0
  S  S37  1  0.790  0.203  0.079  1.0
  S  S38  1  0.788  0.703  0.079  1.0
  S  S39  1  0.212  0.625  0.921  1.0
  S  S40  1  0.704  0.002  0.810  1.0
  S  S41  1  0.296  0.191  0.190  1.0
  S  S42  1  0.393  0.691  0.190  1.0
  S  S43  1  0.607  0.502  0.810  1.0
  S  S44  1  0.658  0.314  0.903  1.0
  S  S45  1  0.342  0.411  0.097  1.0
  S  S46  1  0.255  0.911  0.097  1.0
  S  S47  1  0.745  0.814  0.903  1.0
[/CIF]
.