The material described by Ba3Si23 crystallizes in the cubic Pm-3n space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 24-coordinate geometry to four Si(1,1,1); eight Si(2,2); and twelve Si(3,3,3,3,3) atoms. In the second Ba site, Ba(1) is bonded in a 24-coordinate geometry to four equivalent Si(1); eight equivalent Si(2); and twelve Si(3,3) atoms. There are ten inequivalent Si sites. In the first Si site, Si(3) is bonded in a 6-coordinate geometry to three equivalent Ba(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the second Si site, Si(1) is bonded to four Ba(1,1) and four Si(3,3,3) atoms to form distorted SiBa4Si4 tetrahedra that share corners with six Si(1,1)Ba4Si4 tetrahedra; corners with sixteen Si(2,2)Ba3Si4 tetrahedra; edges with two equivalent Si(1)Ba4Si4 tetrahedra; and faces with eight Si(2,2)Ba3Si4 tetrahedra. In the third Si site, Si(1) is bonded to four equivalent Ba(1) and four equivalent Si(3) atoms to form distorted SiBa4Si4 tetrahedra that share corners with eight equivalent Si(1)Ba4Si4 tetrahedra, corners with sixteen equivalent Si(2)Ba3Si4 tetrahedra, and faces with eight equivalent Si(2)Ba3Si4 tetrahedra. In the fourth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to four equivalent Ba(1) and four equivalent Si(3) atoms. In the fifth Si site, Si(2) is bonded to three Ba(1,1); one Si(2); and three Si(3,3,3) atoms to form SiBa3Si4 tetrahedra that share corners with four equivalent Si(1)Ba4Si4 tetrahedra; corners with fifteen Si(2,2)Ba3Si4 tetrahedra; edges with three Si(2,2)Ba3Si4 tetrahedra;  a faceface with one Si(2)Ba3Si4 tetrahedra; and faces with three Si(1,1)Ba4Si4 tetrahedra. In the sixth Si site, Si(2) is bonded to three Ba(1,1); one Si(2); and three Si(3,3,3) atoms to form SiBa3Si4 tetrahedra that share corners with six Si(1,1)Ba4Si4 tetrahedra; corners with fifteen Si(2,2)Ba3Si4 tetrahedra; edges with three Si(2,2)Ba3Si4 tetrahedra;  a faceface with one Si(2)Ba3Si4 tetrahedra; and faces with two equivalent Si(1)Ba4Si4 tetrahedra. In the seventh Si site, Si(3) is bonded in a 6-coordinate geometry to three equivalent Ba(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the eighth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two equivalent Si(2) atoms. In the ninth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two equivalent Si(2) atoms. In the tenth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two Si(2,2) atoms. is represented by the CIF card [CIF]
data_Ba3Si23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.311
_cell_length_b   10.311
_cell_length_c   10.311
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1096.117
_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
  Ba  Ba0  1  0.250  0.500  0.000  1.0
  Ba  Ba1  1  0.750  0.500  0.000  1.0
  Ba  Ba2  1  0.500  0.000  0.250  1.0
  Ba  Ba3  1  0.500  0.000  0.750  1.0
  Ba  Ba4  1  0.000  0.750  0.500  1.0
  Ba  Ba5  1  0.000  0.250  0.500  1.0
  Si  Si6  1  0.250  0.000  0.500  1.0
  Si  Si7  1  0.750  0.000  0.500  1.0
  Si  Si8  1  0.000  0.500  0.250  1.0
  Si  Si9  1  0.000  0.500  0.750  1.0
  Si  Si10  1  0.500  0.750  0.000  1.0
  Si  Si11  1  0.500  0.250  0.000  1.0
  Si  Si12  1  0.184  0.184  0.184  1.0
  Si  Si13  1  0.684  0.316  0.684  1.0
  Si  Si14  1  0.684  0.684  0.316  1.0
  Si  Si15  1  0.316  0.684  0.684  1.0
  Si  Si16  1  0.816  0.816  0.184  1.0
  Si  Si17  1  0.184  0.816  0.816  1.0
  Si  Si18  1  0.816  0.184  0.816  1.0
  Si  Si19  1  0.316  0.316  0.316  1.0
  Si  Si20  1  0.816  0.816  0.816  1.0
  Si  Si21  1  0.316  0.684  0.316  1.0
  Si  Si22  1  0.316  0.316  0.684  1.0
  Si  Si23  1  0.684  0.316  0.316  1.0
  Si  Si24  1  0.184  0.184  0.816  1.0
  Si  Si25  1  0.816  0.184  0.184  1.0
  Si  Si26  1  0.184  0.816  0.184  1.0
  Si  Si27  1  0.684  0.684  0.684  1.0
  Si  Si28  1  0.000  0.304  0.121  1.0
  Si  Si29  1  0.500  0.379  0.804  1.0
  Si  Si30  1  0.500  0.621  0.196  1.0
  Si  Si31  1  0.621  0.804  0.500  1.0
  Si  Si32  1  0.379  0.804  0.500  1.0
  Si  Si33  1  0.196  0.500  0.621  1.0
  Si  Si34  1  0.804  0.500  0.621  1.0
  Si  Si35  1  0.121  0.000  0.304  1.0
  Si  Si36  1  0.304  0.121  0.000  1.0
  Si  Si37  1  0.696  0.879  0.000  1.0
  Si  Si38  1  0.121  0.000  0.696  1.0
  Si  Si39  1  0.696  0.121  0.000  1.0
  Si  Si40  1  0.879  0.000  0.304  1.0
  Si  Si41  1  0.879  0.000  0.696  1.0
  Si  Si42  1  0.304  0.879  0.000  1.0
  Si  Si43  1  0.000  0.696  0.879  1.0
  Si  Si44  1  0.000  0.304  0.879  1.0
  Si  Si45  1  0.000  0.696  0.121  1.0
  Si  Si46  1  0.804  0.500  0.379  1.0
  Si  Si47  1  0.196  0.500  0.379  1.0
  Si  Si48  1  0.621  0.196  0.500  1.0
  Si  Si49  1  0.379  0.196  0.500  1.0
  Si  Si50  1  0.500  0.621  0.804  1.0
  Si  Si51  1  0.500  0.379  0.196  1.0
[/CIF]
.
The material described by Ba3Si23 crystallizes in the cubic Pm-3n space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 24-coordinate geometry to four Si(1,1,1); eight Si(2,2); and twelve Si(3,3,3,3,3) atoms. In the second Ba site, Ba(1) is bonded in a 24-coordinate geometry to four equivalent Si(1); eight equivalent Si(2); and twelve Si(3,3) atoms. There are ten inequivalent Si sites. In the first Si site, Si(3) is bonded in a 6-coordinate geometry to three equivalent Ba(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the second Si site, Si(1) is bonded to four Ba(1,1) and four Si(3,3,3) atoms to form distorted SiBa4Si4 tetrahedra that share corners with six Si(1,1)Ba4Si4 tetrahedra; corners with sixteen Si(2,2)Ba3Si4 tetrahedra; edges with two equivalent Si(1)Ba4Si4 tetrahedra; and faces with eight Si(2,2)Ba3Si4 tetrahedra. In the third Si site, Si(1) is bonded to four equivalent Ba(1) and four equivalent Si(3) atoms to form distorted SiBa4Si4 tetrahedra that share corners with eight equivalent Si(1)Ba4Si4 tetrahedra, corners with sixteen equivalent Si(2)Ba3Si4 tetrahedra, and faces with eight equivalent Si(2)Ba3Si4 tetrahedra. In the fourth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to four equivalent Ba(1) and four equivalent Si(3) atoms. In the fifth Si site, Si(2) is bonded to three Ba(1,1); one Si(2); and three Si(3,3,3) atoms to form SiBa3Si4 tetrahedra that share corners with four equivalent Si(1)Ba4Si4 tetrahedra; corners with fifteen Si(2,2)Ba3Si4 tetrahedra; edges with three Si(2,2)Ba3Si4 tetrahedra;  a faceface with one Si(2)Ba3Si4 tetrahedra; and faces with three Si(1,1)Ba4Si4 tetrahedra. In the sixth Si site, Si(2) is bonded to three Ba(1,1); one Si(2); and three Si(3,3,3) atoms to form SiBa3Si4 tetrahedra that share corners with six Si(1,1)Ba4Si4 tetrahedra; corners with fifteen Si(2,2)Ba3Si4 tetrahedra; edges with three Si(2,2)Ba3Si4 tetrahedra;  a faceface with one Si(2)Ba3Si4 tetrahedra; and faces with two equivalent Si(1)Ba4Si4 tetrahedra. In the seventh Si site, Si(3) is bonded in a 6-coordinate geometry to three equivalent Ba(1), one Si(1), one Si(3), and two equivalent Si(2) atoms. In the eighth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two equivalent Si(2) atoms. In the ninth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two equivalent Si(2) atoms. In the tenth Si site, Si(3) is bonded in a 6-coordinate geometry to three Ba(1,1); one Si(1); one Si(3); and two Si(2,2) atoms. is represented by the CIF card [CIF]
data_Ba3Si23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.311
_cell_length_b   10.311
_cell_length_c   10.311
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1096.117
_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
  Ba  Ba0  1  0.250  0.500  0.000  1.0
  Ba  Ba1  1  0.750  0.500  0.000  1.0
  Ba  Ba2  1  0.500  0.000  0.250  1.0
  Ba  Ba3  1  0.500  0.000  0.750  1.0
  Ba  Ba4  1  0.000  0.750  0.500  1.0
  Ba  Ba5  1  0.000  0.250  0.500  1.0
  Si  Si6  1  0.250  0.000  0.500  1.0
  Si  Si7  1  0.750  0.000  0.500  1.0
  Si  Si8  1  0.000  0.500  0.250  1.0
  Si  Si9  1  0.000  0.500  0.750  1.0
  Si  Si10  1  0.500  0.750  0.000  1.0
  Si  Si11  1  0.500  0.250  0.000  1.0
  Si  Si12  1  0.184  0.184  0.184  1.0
  Si  Si13  1  0.684  0.316  0.684  1.0
  Si  Si14  1  0.684  0.684  0.316  1.0
  Si  Si15  1  0.316  0.684  0.684  1.0
  Si  Si16  1  0.816  0.816  0.184  1.0
  Si  Si17  1  0.184  0.816  0.816  1.0
  Si  Si18  1  0.816  0.184  0.816  1.0
  Si  Si19  1  0.316  0.316  0.316  1.0
  Si  Si20  1  0.816  0.816  0.816  1.0
  Si  Si21  1  0.316  0.684  0.316  1.0
  Si  Si22  1  0.316  0.316  0.684  1.0
  Si  Si23  1  0.684  0.316  0.316  1.0
  Si  Si24  1  0.184  0.184  0.816  1.0
  Si  Si25  1  0.816  0.184  0.184  1.0
  Si  Si26  1  0.184  0.816  0.184  1.0
  Si  Si27  1  0.684  0.684  0.684  1.0
  Si  Si28  1  0.000  0.304  0.121  1.0
  Si  Si29  1  0.500  0.379  0.804  1.0
  Si  Si30  1  0.500  0.621  0.196  1.0
  Si  Si31  1  0.621  0.804  0.500  1.0
  Si  Si32  1  0.379  0.804  0.500  1.0
  Si  Si33  1  0.196  0.500  0.621  1.0
  Si  Si34  1  0.804  0.500  0.621  1.0
  Si  Si35  1  0.121  0.000  0.304  1.0
  Si  Si36  1  0.304  0.121  0.000  1.0
  Si  Si37  1  0.696  0.879  0.000  1.0
  Si  Si38  1  0.121  0.000  0.696  1.0
  Si  Si39  1  0.696  0.121  0.000  1.0
  Si  Si40  1  0.879  0.000  0.304  1.0
  Si  Si41  1  0.879  0.000  0.696  1.0
  Si  Si42  1  0.304  0.879  0.000  1.0
  Si  Si43  1  0.000  0.696  0.879  1.0
  Si  Si44  1  0.000  0.304  0.879  1.0
  Si  Si45  1  0.000  0.696  0.121  1.0
  Si  Si46  1  0.804  0.500  0.379  1.0
  Si  Si47  1  0.196  0.500  0.379  1.0
  Si  Si48  1  0.621  0.196  0.500  1.0
  Si  Si49  1  0.379  0.196  0.500  1.0
  Si  Si50  1  0.500  0.621  0.804  1.0
  Si  Si51  1  0.500  0.379  0.196  1.0
[/CIF]
.