The compound described by Ba4Si3Br2 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), two equivalent Br(2), and three equivalent Br(1) atoms. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to two equivalent Si(2), three equivalent Si(1), and one Br(2) atom. In the fourth Ba site, Ba(4) is bonded in a 8-coordinate geometry to one Si(2), two equivalent Si(3), two equivalent Br(2), and three equivalent Br(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Ba(2), three equivalent Ba(3), four equivalent Ba(1), one Si(2), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Ba(4), two equivalent Ba(1), two equivalent Ba(2), two equivalent Ba(3), one Si(1), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Ba(2), two equivalent Ba(1), two equivalent Ba(4), one Si(1), and one Si(2) atom. There are two inequivalent Br sites. In the first Br site, Br(2) is bonded to one Ba(3), two equivalent Ba(2), and two equivalent Ba(4) atoms to form BrBa5 square pyramids that share corners with four equivalent Br(1)Ba6 pentagonal pyramids, corners with four equivalent Br(2)Ba5 square pyramids, and edges with four equivalent Br(1)Ba6 pentagonal pyramids. In the second Br site, Br(1) is bonded to three equivalent Ba(2) and three equivalent Ba(4) atoms to form distorted BrBa6 pentagonal pyramids that share corners with four equivalent Br(2)Ba5 square pyramids, edges with four equivalent Br(1)Ba6 pentagonal pyramids, edges with four equivalent Br(2)Ba5 square pyramids, and  a faceface with one Br(1)Ba6 pentagonal pyramid. is represented by the CIF file [CIF]
data_Ba4Si3Br2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.949
_cell_length_b   8.900
_cell_length_c   15.207
_cell_angle_alpha   78.023
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1184.833
_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  0.711  0.521  0.956  1.0
  Ba  Ba1  1  0.211  0.979  0.044  1.0
  Ba  Ba2  1  0.289  0.479  0.044  1.0
  Ba  Ba3  1  0.789  0.021  0.956  1.0
  Ba  Ba4  1  0.662  0.734  0.332  1.0
  Ba  Ba5  1  0.162  0.766  0.668  1.0
  Ba  Ba6  1  0.338  0.266  0.668  1.0
  Ba  Ba7  1  0.838  0.234  0.332  1.0
  Ba  Ba8  1  0.060  0.372  0.853  1.0
  Ba  Ba9  1  0.560  0.128  0.147  1.0
  Ba  Ba10  1  0.940  0.628  0.147  1.0
  Ba  Ba11  1  0.440  0.872  0.853  1.0
  Ba  Ba12  1  0.678  0.619  0.652  1.0
  Ba  Ba13  1  0.178  0.881  0.348  1.0
  Ba  Ba14  1  0.322  0.381  0.348  1.0
  Ba  Ba15  1  0.822  0.119  0.652  1.0
  Si  Si16  1  0.063  0.741  0.912  1.0
  Si  Si17  1  0.563  0.759  0.088  1.0
  Si  Si18  1  0.937  0.259  0.088  1.0
  Si  Si19  1  0.437  0.241  0.912  1.0
  Si  Si20  1  0.433  0.492  0.814  1.0
  Si  Si21  1  0.933  0.008  0.186  1.0
  Si  Si22  1  0.567  0.508  0.186  1.0
  Si  Si23  1  0.067  0.992  0.814  1.0
  Si  Si24  1  0.630  0.304  0.801  1.0
  Si  Si25  1  0.130  0.196  0.199  1.0
  Si  Si26  1  0.370  0.696  0.199  1.0
  Si  Si27  1  0.870  0.804  0.801  1.0
  Br  Br28  1  0.360  0.634  0.507  1.0
  Br  Br29  1  0.860  0.866  0.493  1.0
  Br  Br30  1  0.640  0.366  0.493  1.0
  Br  Br31  1  0.140  0.134  0.507  1.0
  Br  Br32  1  0.493  0.948  0.635  1.0
  Br  Br33  1  0.993  0.552  0.365  1.0
  Br  Br34  1  0.507  0.052  0.365  1.0
  Br  Br35  1  0.007  0.448  0.635  1.0
[/CIF]
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The compound described by Ba4Si3Br2 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to two equivalent Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), two equivalent Br(2), and three equivalent Br(1) atoms. In the third Ba site, Ba(3) is bonded in a 6-coordinate geometry to two equivalent Si(2), three equivalent Si(1), and one Br(2) atom. In the fourth Ba site, Ba(4) is bonded in a 8-coordinate geometry to one Si(2), two equivalent Si(3), two equivalent Br(2), and three equivalent Br(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Ba(2), three equivalent Ba(3), four equivalent Ba(1), one Si(2), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Ba(4), two equivalent Ba(1), two equivalent Ba(2), two equivalent Ba(3), one Si(1), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Ba(2), two equivalent Ba(1), two equivalent Ba(4), one Si(1), and one Si(2) atom. There are two inequivalent Br sites. In the first Br site, Br(2) is bonded to one Ba(3), two equivalent Ba(2), and two equivalent Ba(4) atoms to form BrBa5 square pyramids that share corners with four equivalent Br(1)Ba6 pentagonal pyramids, corners with four equivalent Br(2)Ba5 square pyramids, and edges with four equivalent Br(1)Ba6 pentagonal pyramids. In the second Br site, Br(1) is bonded to three equivalent Ba(2) and three equivalent Ba(4) atoms to form distorted BrBa6 pentagonal pyramids that share corners with four equivalent Br(2)Ba5 square pyramids, edges with four equivalent Br(1)Ba6 pentagonal pyramids, edges with four equivalent Br(2)Ba5 square pyramids, and  a faceface with one Br(1)Ba6 pentagonal pyramid. is represented by the CIF file [CIF]
data_Ba4Si3Br2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.949
_cell_length_b   8.900
_cell_length_c   15.207
_cell_angle_alpha   78.023
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1184.833
_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  0.711  0.521  0.956  1.0
  Ba  Ba1  1  0.211  0.979  0.044  1.0
  Ba  Ba2  1  0.289  0.479  0.044  1.0
  Ba  Ba3  1  0.789  0.021  0.956  1.0
  Ba  Ba4  1  0.662  0.734  0.332  1.0
  Ba  Ba5  1  0.162  0.766  0.668  1.0
  Ba  Ba6  1  0.338  0.266  0.668  1.0
  Ba  Ba7  1  0.838  0.234  0.332  1.0
  Ba  Ba8  1  0.060  0.372  0.853  1.0
  Ba  Ba9  1  0.560  0.128  0.147  1.0
  Ba  Ba10  1  0.940  0.628  0.147  1.0
  Ba  Ba11  1  0.440  0.872  0.853  1.0
  Ba  Ba12  1  0.678  0.619  0.652  1.0
  Ba  Ba13  1  0.178  0.881  0.348  1.0
  Ba  Ba14  1  0.322  0.381  0.348  1.0
  Ba  Ba15  1  0.822  0.119  0.652  1.0
  Si  Si16  1  0.063  0.741  0.912  1.0
  Si  Si17  1  0.563  0.759  0.088  1.0
  Si  Si18  1  0.937  0.259  0.088  1.0
  Si  Si19  1  0.437  0.241  0.912  1.0
  Si  Si20  1  0.433  0.492  0.814  1.0
  Si  Si21  1  0.933  0.008  0.186  1.0
  Si  Si22  1  0.567  0.508  0.186  1.0
  Si  Si23  1  0.067  0.992  0.814  1.0
  Si  Si24  1  0.630  0.304  0.801  1.0
  Si  Si25  1  0.130  0.196  0.199  1.0
  Si  Si26  1  0.370  0.696  0.199  1.0
  Si  Si27  1  0.870  0.804  0.801  1.0
  Br  Br28  1  0.360  0.634  0.507  1.0
  Br  Br29  1  0.860  0.866  0.493  1.0
  Br  Br30  1  0.640  0.366  0.493  1.0
  Br  Br31  1  0.140  0.134  0.507  1.0
  Br  Br32  1  0.493  0.948  0.635  1.0
  Br  Br33  1  0.993  0.552  0.365  1.0
  Br  Br34  1  0.507  0.052  0.365  1.0
  Br  Br35  1  0.007  0.448  0.635  1.0
[/CIF]
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