The material described by Ba3Si2B6O16 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(1), one O(4), one O(8), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form BO4 tetrahedra that share  a cornercorner with one B(3)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(4), and one O(5) atom. In the third B site, B(3) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form BO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent B(1)O4 tetrahedra and corners with two equivalent B(3)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2), one B(3), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Ba(2), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(2), one B(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one B(2), and one B(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one B(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one B(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one B(1), and one B(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Ba(1), one Ba(2), one B(3), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ba3Si2(B3O8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.084
_cell_length_b   7.682
_cell_length_c   8.630
_cell_angle_alpha   102.819
_cell_angle_beta   102.298
_cell_angle_gamma   87.293
_symmetry_Int_Tables_number   1
_cell_volume   321.079
_cell_formula_units_Z   1
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  0.500  0.000  0.500  1.0
  Ba  Ba1  1  0.381  0.420  0.235  1.0
  Ba  Ba2  1  0.619  0.580  0.765  1.0
  Si  Si3  1  0.760  0.174  0.940  1.0
  Si  Si4  1  0.240  0.826  0.060  1.0
  B  B5  1  0.184  0.239  0.796  1.0
  B  B6  1  0.816  0.761  0.204  1.0
  B  B7  1  0.031  0.697  0.476  1.0
  B  B8  1  0.969  0.303  0.524  1.0
  B  B9  1  0.978  0.091  0.246  1.0
  B  B10  1  0.022  0.909  0.754  1.0
  O  O11  1  0.785  0.178  0.133  1.0
  O  O12  1  0.215  0.822  0.867  1.0
  O  O13  1  0.855  0.642  0.322  1.0
  O  O14  1  0.145  0.358  0.678  1.0
  O  O15  1  0.002  0.294  0.915  1.0
  O  O16  1  0.998  0.706  0.085  1.0
  O  O17  1  0.095  0.226  0.395  1.0
  O  O18  1  0.905  0.774  0.605  1.0
  O  O19  1  0.299  0.676  0.494  1.0
  O  O20  1  0.701  0.324  0.506  1.0
  O  O21  1  0.528  0.727  0.111  1.0
  O  O22  1  0.472  0.273  0.889  1.0
  O  O23  1  0.136  0.055  0.706  1.0
  O  O24  1  0.864  0.945  0.294  1.0
  O  O25  1  0.221  0.027  0.173  1.0
  O  O26  1  0.779  0.973  0.827  1.0
[/CIF]
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The material described by Ba3Si2B6O16 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(1), one O(4), one O(8), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form BO4 tetrahedra that share  a cornercorner with one B(3)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(2), one O(4), and one O(5) atom. In the third B site, B(3) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form BO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra and corners with two equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent B(1)O4 tetrahedra and corners with two equivalent B(3)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Ba(2), one B(3), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Ba(2), one B(1), and one B(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(2), one B(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one B(2), and one B(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one B(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one B(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one B(1), and one B(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Ba(1), one Ba(2), one B(3), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ba3Si2(B3O8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.084
_cell_length_b   7.682
_cell_length_c   8.630
_cell_angle_alpha   102.819
_cell_angle_beta   102.298
_cell_angle_gamma   87.293
_symmetry_Int_Tables_number   1
_cell_volume   321.079
_cell_formula_units_Z   1
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  0.500  0.000  0.500  1.0
  Ba  Ba1  1  0.381  0.420  0.235  1.0
  Ba  Ba2  1  0.619  0.580  0.765  1.0
  Si  Si3  1  0.760  0.174  0.940  1.0
  Si  Si4  1  0.240  0.826  0.060  1.0
  B  B5  1  0.184  0.239  0.796  1.0
  B  B6  1  0.816  0.761  0.204  1.0
  B  B7  1  0.031  0.697  0.476  1.0
  B  B8  1  0.969  0.303  0.524  1.0
  B  B9  1  0.978  0.091  0.246  1.0
  B  B10  1  0.022  0.909  0.754  1.0
  O  O11  1  0.785  0.178  0.133  1.0
  O  O12  1  0.215  0.822  0.867  1.0
  O  O13  1  0.855  0.642  0.322  1.0
  O  O14  1  0.145  0.358  0.678  1.0
  O  O15  1  0.002  0.294  0.915  1.0
  O  O16  1  0.998  0.706  0.085  1.0
  O  O17  1  0.095  0.226  0.395  1.0
  O  O18  1  0.905  0.774  0.605  1.0
  O  O19  1  0.299  0.676  0.494  1.0
  O  O20  1  0.701  0.324  0.506  1.0
  O  O21  1  0.528  0.727  0.111  1.0
  O  O22  1  0.472  0.273  0.889  1.0
  O  O23  1  0.136  0.055  0.706  1.0
  O  O24  1  0.864  0.945  0.294  1.0
  O  O25  1  0.221  0.027  0.173  1.0
  O  O26  1  0.779  0.973  0.827  1.0
[/CIF]
.