The crystal structure described by Ba3Sn2S7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one S(3), one S(5), one S(6), one S(7), two equivalent S(2), and two equivalent S(4) atoms. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one S(2), one S(7), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one S(1), one S(2), one S(5), one S(7), two equivalent S(6), and three equivalent S(3) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(1), one S(4), one S(6), and one S(7) atom to form corner-sharing SnS4 tetrahedra. In the second Sn site, Sn(2) is bonded to one S(1), one S(2), one S(3), and one S(5) atom to form corner-sharing SnS4 tetrahedra. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to one Ba(3), two equivalent Ba(2), one Sn(1), and one Sn(2) atom. In the second S site, S(2) is bonded in a 4-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), and one Sn(2) atom. In the third S site, S(3) is bonded to one Ba(1), three equivalent Ba(3), and one Sn(2) atom to form distorted SBa4Sn trigonal bipyramids that share corners with two equivalent S(3)Ba4Sn trigonal bipyramids, corners with four equivalent S(7)Ba3Sn trigonal pyramids, corners with five equivalent S(6)Ba3Sn trigonal pyramids, edges with two equivalent S(3)Ba4Sn trigonal bipyramids, and  an edgeedge with one S(6)Ba3Sn trigonal pyramid. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Sn(1) atom. In the fifth S site, S(5) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), and one Sn(2) atom. In the sixth S site, S(6) is bonded to one Ba(1), two equivalent Ba(3), and one Sn(1) atom to form distorted SBa3Sn trigonal pyramids that share corners with five equivalent S(3)Ba4Sn trigonal bipyramids, corners with two equivalent S(6)Ba3Sn trigonal pyramids, corners with two equivalent S(7)Ba3Sn trigonal pyramids,  an edgeedge with one S(3)Ba4Sn trigonal bipyramid, and  an edgeedge with one S(7)Ba3Sn trigonal pyramid. In the seventh S site, S(7) is bonded to one Ba(1), one Ba(2), one Ba(3), and one Sn(1) atom to form distorted SBa3Sn trigonal pyramids that share corners with four equivalent S(3)Ba4Sn trigonal bipyramids, corners with two equivalent S(6)Ba3Sn trigonal pyramids, and  an edgeedge with one S(6)Ba3Sn trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Sn2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.858
_cell_length_b   11.202
_cell_length_c   18.926
_cell_angle_alpha   79.360
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1429.021
_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
  Ba  Ba0  1  0.775  0.257  0.335  1.0
  Ba  Ba1  1  0.781  0.487  0.609  1.0
  Ba  Ba2  1  0.219  0.513  0.391  1.0
  Ba  Ba3  1  0.267  0.942  0.389  1.0
  Ba  Ba4  1  0.733  0.058  0.611  1.0
  Ba  Ba5  1  0.233  0.942  0.889  1.0
  Ba  Ba6  1  0.275  0.743  0.165  1.0
  Ba  Ba7  1  0.281  0.513  0.891  1.0
  Ba  Ba8  1  0.225  0.743  0.665  1.0
  Ba  Ba9  1  0.767  0.058  0.111  1.0
  Ba  Ba10  1  0.725  0.257  0.835  1.0
  Ba  Ba11  1  0.719  0.487  0.109  1.0
  Sn  Sn12  1  0.301  0.275  0.696  1.0
  Sn  Sn13  1  0.796  0.794  0.496  1.0
  Sn  Sn14  1  0.801  0.725  0.804  1.0
  Sn  Sn15  1  0.699  0.725  0.304  1.0
  Sn  Sn16  1  0.704  0.794  0.996  1.0
  Sn  Sn17  1  0.204  0.206  0.504  1.0
  Sn  Sn18  1  0.199  0.275  0.196  1.0
  Sn  Sn19  1  0.296  0.206  0.004  1.0
  S  S20  1  0.579  0.676  0.432  1.0
  S  S21  1  0.181  0.233  0.883  1.0
  S  S22  1  0.725  0.998  0.940  1.0
  S  S23  1  0.560  0.548  0.269  1.0
  S  S24  1  0.595  0.317  0.990  1.0
  S  S25  1  0.471  0.096  0.747  1.0
  S  S26  1  0.041  0.751  0.307  1.0
  S  S27  1  0.225  0.002  0.560  1.0
  S  S28  1  0.421  0.324  0.568  1.0
  S  S29  1  0.275  0.002  0.060  1.0
  S  S30  1  0.921  0.676  0.932  1.0
  S  S31  1  0.060  0.452  0.231  1.0
  S  S32  1  0.440  0.452  0.731  1.0
  S  S33  1  0.541  0.249  0.193  1.0
  S  S34  1  0.095  0.683  0.510  1.0
  S  S35  1  0.319  0.233  0.383  1.0
  S  S36  1  0.529  0.904  0.253  1.0
  S  S37  1  0.905  0.317  0.490  1.0
  S  S38  1  0.405  0.683  0.010  1.0
  S  S39  1  0.775  0.998  0.440  1.0
  S  S40  1  0.959  0.249  0.693  1.0
  S  S41  1  0.819  0.767  0.117  1.0
  S  S42  1  0.940  0.548  0.769  1.0
  S  S43  1  0.971  0.904  0.753  1.0
  S  S44  1  0.459  0.751  0.807  1.0
  S  S45  1  0.681  0.767  0.617  1.0
  S  S46  1  0.029  0.096  0.247  1.0
  S  S47  1  0.079  0.324  0.068  1.0
[/CIF]
.
The crystal structure described by Ba3Sn2S7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one S(3), one S(5), one S(6), one S(7), two equivalent S(2), and two equivalent S(4) atoms. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one S(2), one S(7), two equivalent S(1), two equivalent S(4), and two equivalent S(5) atoms. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one S(1), one S(2), one S(5), one S(7), two equivalent S(6), and three equivalent S(3) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one S(1), one S(4), one S(6), and one S(7) atom to form corner-sharing SnS4 tetrahedra. In the second Sn site, Sn(2) is bonded to one S(1), one S(2), one S(3), and one S(5) atom to form corner-sharing SnS4 tetrahedra. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to one Ba(3), two equivalent Ba(2), one Sn(1), and one Sn(2) atom. In the second S site, S(2) is bonded in a 4-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), and one Sn(2) atom. In the third S site, S(3) is bonded to one Ba(1), three equivalent Ba(3), and one Sn(2) atom to form distorted SBa4Sn trigonal bipyramids that share corners with two equivalent S(3)Ba4Sn trigonal bipyramids, corners with four equivalent S(7)Ba3Sn trigonal pyramids, corners with five equivalent S(6)Ba3Sn trigonal pyramids, edges with two equivalent S(3)Ba4Sn trigonal bipyramids, and  an edgeedge with one S(6)Ba3Sn trigonal pyramid. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Sn(1) atom. In the fifth S site, S(5) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), and one Sn(2) atom. In the sixth S site, S(6) is bonded to one Ba(1), two equivalent Ba(3), and one Sn(1) atom to form distorted SBa3Sn trigonal pyramids that share corners with five equivalent S(3)Ba4Sn trigonal bipyramids, corners with two equivalent S(6)Ba3Sn trigonal pyramids, corners with two equivalent S(7)Ba3Sn trigonal pyramids,  an edgeedge with one S(3)Ba4Sn trigonal bipyramid, and  an edgeedge with one S(7)Ba3Sn trigonal pyramid. In the seventh S site, S(7) is bonded to one Ba(1), one Ba(2), one Ba(3), and one Sn(1) atom to form distorted SBa3Sn trigonal pyramids that share corners with four equivalent S(3)Ba4Sn trigonal bipyramids, corners with two equivalent S(6)Ba3Sn trigonal pyramids, and  an edgeedge with one S(6)Ba3Sn trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Sn2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.858
_cell_length_b   11.202
_cell_length_c   18.926
_cell_angle_alpha   79.360
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1429.021
_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
  Ba  Ba0  1  0.775  0.257  0.335  1.0
  Ba  Ba1  1  0.781  0.487  0.609  1.0
  Ba  Ba2  1  0.219  0.513  0.391  1.0
  Ba  Ba3  1  0.267  0.942  0.389  1.0
  Ba  Ba4  1  0.733  0.058  0.611  1.0
  Ba  Ba5  1  0.233  0.942  0.889  1.0
  Ba  Ba6  1  0.275  0.743  0.165  1.0
  Ba  Ba7  1  0.281  0.513  0.891  1.0
  Ba  Ba8  1  0.225  0.743  0.665  1.0
  Ba  Ba9  1  0.767  0.058  0.111  1.0
  Ba  Ba10  1  0.725  0.257  0.835  1.0
  Ba  Ba11  1  0.719  0.487  0.109  1.0
  Sn  Sn12  1  0.301  0.275  0.696  1.0
  Sn  Sn13  1  0.796  0.794  0.496  1.0
  Sn  Sn14  1  0.801  0.725  0.804  1.0
  Sn  Sn15  1  0.699  0.725  0.304  1.0
  Sn  Sn16  1  0.704  0.794  0.996  1.0
  Sn  Sn17  1  0.204  0.206  0.504  1.0
  Sn  Sn18  1  0.199  0.275  0.196  1.0
  Sn  Sn19  1  0.296  0.206  0.004  1.0
  S  S20  1  0.579  0.676  0.432  1.0
  S  S21  1  0.181  0.233  0.883  1.0
  S  S22  1  0.725  0.998  0.940  1.0
  S  S23  1  0.560  0.548  0.269  1.0
  S  S24  1  0.595  0.317  0.990  1.0
  S  S25  1  0.471  0.096  0.747  1.0
  S  S26  1  0.041  0.751  0.307  1.0
  S  S27  1  0.225  0.002  0.560  1.0
  S  S28  1  0.421  0.324  0.568  1.0
  S  S29  1  0.275  0.002  0.060  1.0
  S  S30  1  0.921  0.676  0.932  1.0
  S  S31  1  0.060  0.452  0.231  1.0
  S  S32  1  0.440  0.452  0.731  1.0
  S  S33  1  0.541  0.249  0.193  1.0
  S  S34  1  0.095  0.683  0.510  1.0
  S  S35  1  0.319  0.233  0.383  1.0
  S  S36  1  0.529  0.904  0.253  1.0
  S  S37  1  0.905  0.317  0.490  1.0
  S  S38  1  0.405  0.683  0.010  1.0
  S  S39  1  0.775  0.998  0.440  1.0
  S  S40  1  0.959  0.249  0.693  1.0
  S  S41  1  0.819  0.767  0.117  1.0
  S  S42  1  0.940  0.548  0.769  1.0
  S  S43  1  0.971  0.904  0.753  1.0
  S  S44  1  0.459  0.751  0.807  1.0
  S  S45  1  0.681  0.767  0.617  1.0
  S  S46  1  0.029  0.096  0.247  1.0
  S  S47  1  0.079  0.324  0.068  1.0
[/CIF]
.