The material described by Ba9Sc2Si6O24 crystallizes in the trigonal R-3 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(4) atoms. In the third Ba site, Ba(3) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share edges with six equivalent Si(1)O4 tetrahedra and faces with two equivalent Sc(1)O6 octahedra. Sc(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form ScO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and  a faceface with one Ba(3)O12 cuboctahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Sc(1)O6 octahedra and  an edgeedge with one Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(3), three equivalent Ba(1), one Sc(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Sc(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_Ba9Sc2(SiO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.395
_cell_length_b   9.395
_cell_length_c   9.395
_cell_angle_alpha   64.308
_cell_angle_beta   64.308
_cell_angle_gamma   64.308
_symmetry_Int_Tables_number   1
_cell_volume   641.836
_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  0.563  0.864  0.248  1.0
  Ba  Ba1  1  0.663  0.663  0.663  1.0
  Ba  Ba2  1  0.752  0.437  0.136  1.0
  Ba  Ba3  1  0.864  0.248  0.563  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Ba  Ba5  1  0.136  0.752  0.437  1.0
  Ba  Ba6  1  0.437  0.136  0.752  1.0
  Ba  Ba7  1  0.337  0.337  0.337  1.0
  Ba  Ba8  1  0.248  0.563  0.864  1.0
  Sc  Sc9  1  0.835  0.835  0.835  1.0
  Sc  Sc10  1  0.165  0.165  0.165  1.0
  Si  Si11  1  0.415  0.764  0.050  1.0
  Si  Si12  1  0.050  0.415  0.764  1.0
  Si  Si13  1  0.764  0.050  0.415  1.0
  Si  Si14  1  0.950  0.585  0.236  1.0
  Si  Si15  1  0.236  0.950  0.585  1.0
  Si  Si16  1  0.585  0.236  0.950  1.0
  O  O17  1  0.364  0.726  0.929  1.0
  O  O18  1  0.904  0.717  0.061  1.0
  O  O19  1  0.096  0.283  0.939  1.0
  O  O20  1  0.929  0.364  0.726  1.0
  O  O21  1  0.773  0.569  0.379  1.0
  O  O22  1  0.379  0.773  0.569  1.0
  O  O23  1  0.717  0.061  0.904  1.0
  O  O24  1  0.061  0.904  0.717  1.0
  O  O25  1  0.636  0.274  0.071  1.0
  O  O26  1  0.051  0.396  0.210  1.0
  O  O27  1  0.949  0.604  0.790  1.0
  O  O28  1  0.569  0.379  0.773  1.0
  O  O29  1  0.396  0.210  0.051  1.0
  O  O30  1  0.274  0.071  0.636  1.0
  O  O31  1  0.790  0.949  0.604  1.0
  O  O32  1  0.621  0.227  0.431  1.0
  O  O33  1  0.071  0.636  0.274  1.0
  O  O34  1  0.431  0.621  0.227  1.0
  O  O35  1  0.604  0.790  0.949  1.0
  O  O36  1  0.939  0.096  0.283  1.0
  O  O37  1  0.726  0.929  0.364  1.0
  O  O38  1  0.227  0.431  0.621  1.0
  O  O39  1  0.283  0.939  0.096  1.0
  O  O40  1  0.210  0.051  0.396  1.0
[/CIF]
.
The material described by Ba9Sc2Si6O24 crystallizes in the trigonal R-3 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(4) atoms. In the third Ba site, Ba(3) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share edges with six equivalent Si(1)O4 tetrahedra and faces with two equivalent Sc(1)O6 octahedra. Sc(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form ScO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and  a faceface with one Ba(3)O12 cuboctahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Sc(1)O6 octahedra and  an edgeedge with one Ba(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(3), three equivalent Ba(1), one Sc(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Sc(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_Ba9Sc2(SiO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.395
_cell_length_b   9.395
_cell_length_c   9.395
_cell_angle_alpha   64.308
_cell_angle_beta   64.308
_cell_angle_gamma   64.308
_symmetry_Int_Tables_number   1
_cell_volume   641.836
_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  0.563  0.864  0.248  1.0
  Ba  Ba1  1  0.663  0.663  0.663  1.0
  Ba  Ba2  1  0.752  0.437  0.136  1.0
  Ba  Ba3  1  0.864  0.248  0.563  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Ba  Ba5  1  0.136  0.752  0.437  1.0
  Ba  Ba6  1  0.437  0.136  0.752  1.0
  Ba  Ba7  1  0.337  0.337  0.337  1.0
  Ba  Ba8  1  0.248  0.563  0.864  1.0
  Sc  Sc9  1  0.835  0.835  0.835  1.0
  Sc  Sc10  1  0.165  0.165  0.165  1.0
  Si  Si11  1  0.415  0.764  0.050  1.0
  Si  Si12  1  0.050  0.415  0.764  1.0
  Si  Si13  1  0.764  0.050  0.415  1.0
  Si  Si14  1  0.950  0.585  0.236  1.0
  Si  Si15  1  0.236  0.950  0.585  1.0
  Si  Si16  1  0.585  0.236  0.950  1.0
  O  O17  1  0.364  0.726  0.929  1.0
  O  O18  1  0.904  0.717  0.061  1.0
  O  O19  1  0.096  0.283  0.939  1.0
  O  O20  1  0.929  0.364  0.726  1.0
  O  O21  1  0.773  0.569  0.379  1.0
  O  O22  1  0.379  0.773  0.569  1.0
  O  O23  1  0.717  0.061  0.904  1.0
  O  O24  1  0.061  0.904  0.717  1.0
  O  O25  1  0.636  0.274  0.071  1.0
  O  O26  1  0.051  0.396  0.210  1.0
  O  O27  1  0.949  0.604  0.790  1.0
  O  O28  1  0.569  0.379  0.773  1.0
  O  O29  1  0.396  0.210  0.051  1.0
  O  O30  1  0.274  0.071  0.636  1.0
  O  O31  1  0.790  0.949  0.604  1.0
  O  O32  1  0.621  0.227  0.431  1.0
  O  O33  1  0.071  0.636  0.274  1.0
  O  O34  1  0.431  0.621  0.227  1.0
  O  O35  1  0.604  0.790  0.949  1.0
  O  O36  1  0.939  0.096  0.283  1.0
  O  O37  1  0.726  0.929  0.364  1.0
  O  O38  1  0.227  0.431  0.621  1.0
  O  O39  1  0.283  0.939  0.096  1.0
  O  O40  1  0.210  0.051  0.396  1.0
[/CIF]
.