The crystal structure described by Ba8Ca3Nb5O24 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(4), one O(6), two equivalent O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ca(2)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Ca(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, and faces with two equivalent Nb(2)O6 octahedra. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form CaO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Ca site, Ca(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the third Ca site, Ca(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(6), and four equivalent O(1) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Nb site, Nb(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the third Nb site, Nb(3) is bonded to two equivalent O(6) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Ca(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(2), and one Nb(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(2), and one Nb(3) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(2), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded to four equivalent Ba(1), one Nb(1), and one Nb(3) atom to form distorted corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba8Ca3Nb5O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.506
_cell_length_b   10.506
_cell_length_c   10.506
_cell_angle_alpha   132.317
_cell_angle_beta   132.317
_cell_angle_gamma   69.729
_symmetry_Int_Tables_number   1
_cell_volume   621.842
_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  0.629  0.629  0.507  1.0
  Ba  Ba1  1  0.371  0.879  0.000  1.0
  Ba  Ba2  1  0.121  0.121  0.493  1.0
  Ba  Ba3  1  0.879  0.371  0.000  1.0
  Ba  Ba4  1  0.879  0.879  0.507  1.0
  Ba  Ba5  1  0.629  0.121  0.000  1.0
  Ba  Ba6  1  0.371  0.371  0.493  1.0
  Ba  Ba7  1  0.121  0.629  0.000  1.0
  Ca  Ca8  1  0.750  0.250  0.500  1.0
  Ca  Ca9  1  0.500  0.500  0.000  1.0
  Ca  Ca10  1  0.250  0.750  0.500  1.0
  Nb  Nb11  1  0.255  0.255  0.000  1.0
  Nb  Nb12  1  0.000  0.500  0.500  1.0
  Nb  Nb13  1  0.745  0.745  0.000  1.0
  Nb  Nb14  1  0.500  0.000  0.500  1.0
  Nb  Nb15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.474  0.242  0.232  1.0
  O  O17  1  0.232  0.500  0.732  1.0
  O  O18  1  0.991  0.758  0.232  1.0
  O  O19  1  0.755  0.000  0.755  1.0
  O  O20  1  0.366  0.366  0.000  1.0
  O  O21  1  0.115  0.615  0.500  1.0
  O  O22  1  0.885  0.885  0.000  1.0
  O  O23  1  0.615  0.115  0.500  1.0
  O  O24  1  0.242  0.474  0.232  1.0
  O  O25  1  0.000  0.755  0.755  1.0
  O  O26  1  0.758  0.991  0.232  1.0
  O  O27  1  0.500  0.232  0.732  1.0
  O  O28  1  0.009  0.242  0.768  1.0
  O  O29  1  0.768  0.500  0.268  1.0
  O  O30  1  0.526  0.758  0.768  1.0
  O  O31  1  0.245  0.000  0.245  1.0
  O  O32  1  0.115  0.115  0.000  1.0
  O  O33  1  0.885  0.385  0.500  1.0
  O  O34  1  0.634  0.634  0.000  1.0
  O  O35  1  0.385  0.885  0.500  1.0
  O  O36  1  0.242  0.009  0.768  1.0
  O  O37  1  0.000  0.245  0.245  1.0
  O  O38  1  0.758  0.526  0.768  1.0
  O  O39  1  0.500  0.768  0.268  1.0
[/CIF]
.
The crystal structure described by Ba8Ca3Nb5O24 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(4), one O(6), two equivalent O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ca(2)O6 octahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Ca(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, and faces with two equivalent Nb(2)O6 octahedra. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form CaO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Ca site, Ca(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the third Ca site, Ca(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(6), and four equivalent O(1) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Nb(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second Nb site, Nb(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the third Nb site, Nb(3) is bonded to two equivalent O(6) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Ca(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(2), and one Nb(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(1), one Nb(2), and one Nb(3) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(2), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded to four equivalent Ba(1), one Nb(1), and one Nb(3) atom to form distorted corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba8Ca3Nb5O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.506
_cell_length_b   10.506
_cell_length_c   10.506
_cell_angle_alpha   132.317
_cell_angle_beta   132.317
_cell_angle_gamma   69.729
_symmetry_Int_Tables_number   1
_cell_volume   621.842
_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  0.629  0.629  0.507  1.0
  Ba  Ba1  1  0.371  0.879  0.000  1.0
  Ba  Ba2  1  0.121  0.121  0.493  1.0
  Ba  Ba3  1  0.879  0.371  0.000  1.0
  Ba  Ba4  1  0.879  0.879  0.507  1.0
  Ba  Ba5  1  0.629  0.121  0.000  1.0
  Ba  Ba6  1  0.371  0.371  0.493  1.0
  Ba  Ba7  1  0.121  0.629  0.000  1.0
  Ca  Ca8  1  0.750  0.250  0.500  1.0
  Ca  Ca9  1  0.500  0.500  0.000  1.0
  Ca  Ca10  1  0.250  0.750  0.500  1.0
  Nb  Nb11  1  0.255  0.255  0.000  1.0
  Nb  Nb12  1  0.000  0.500  0.500  1.0
  Nb  Nb13  1  0.745  0.745  0.000  1.0
  Nb  Nb14  1  0.500  0.000  0.500  1.0
  Nb  Nb15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.474  0.242  0.232  1.0
  O  O17  1  0.232  0.500  0.732  1.0
  O  O18  1  0.991  0.758  0.232  1.0
  O  O19  1  0.755  0.000  0.755  1.0
  O  O20  1  0.366  0.366  0.000  1.0
  O  O21  1  0.115  0.615  0.500  1.0
  O  O22  1  0.885  0.885  0.000  1.0
  O  O23  1  0.615  0.115  0.500  1.0
  O  O24  1  0.242  0.474  0.232  1.0
  O  O25  1  0.000  0.755  0.755  1.0
  O  O26  1  0.758  0.991  0.232  1.0
  O  O27  1  0.500  0.232  0.732  1.0
  O  O28  1  0.009  0.242  0.768  1.0
  O  O29  1  0.768  0.500  0.268  1.0
  O  O30  1  0.526  0.758  0.768  1.0
  O  O31  1  0.245  0.000  0.245  1.0
  O  O32  1  0.115  0.115  0.000  1.0
  O  O33  1  0.885  0.385  0.500  1.0
  O  O34  1  0.634  0.634  0.000  1.0
  O  O35  1  0.385  0.885  0.500  1.0
  O  O36  1  0.242  0.009  0.768  1.0
  O  O37  1  0.000  0.245  0.245  1.0
  O  O38  1  0.758  0.526  0.768  1.0
  O  O39  1  0.500  0.768  0.268  1.0
[/CIF]
.