The material structure described by Ba5Ca2Ta3O15 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(1), one O(2), one O(7), two equivalent O(3), two equivalent O(4), two equivalent O(5), and three equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with nine equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra, faces with five equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ta(2)O6 octahedra,  a faceface with one Ta(3)O6 octahedra, faces with three equivalent Ca(1)O6 octahedra, and faces with three equivalent Ta(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ca(1)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form CaO6 octahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with five equivalent Ta(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. There are three inequivalent Ta sites. In the first Ta site, Ta(3) is bonded to two equivalent O(7) and four equivalent O(3) atoms to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra, corners with five equivalent Ca(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third Ta site, Ta(2) is bonded to two equivalent O(7) and four equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Ta(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Ta(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1), one Ta(1), and one Ta(3) atom to form a mixture of distorted corner and face-sharing OBa4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one Ta(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 Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ca(1), and one Ta(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ta(2), and one Ta(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba5Ca2Ta3O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.463
_cell_length_b   10.463
_cell_length_c   10.463
_cell_angle_alpha   99.468
_cell_angle_beta   99.468
_cell_angle_gamma   132.144
_symmetry_Int_Tables_number   1
_cell_volume   776.315
_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  0.654  0.953  0.099  1.0
  Ba  Ba1  1  0.047  0.147  0.701  1.0
  Ba  Ba2  1  0.446  0.346  0.299  1.0
  Ba  Ba3  1  0.853  0.554  0.901  1.0
  Ba  Ba4  1  0.250  0.750  0.500  1.0
  Ba  Ba5  1  0.750  0.250  0.500  1.0
  Ba  Ba6  1  0.147  0.446  0.099  1.0
  Ba  Ba7  1  0.554  0.654  0.701  1.0
  Ba  Ba8  1  0.953  0.853  0.299  1.0
  Ba  Ba9  1  0.346  0.047  0.901  1.0
  Ca  Ca10  1  0.399  0.202  0.601  1.0
  Ca  Ca11  1  0.798  0.399  0.197  1.0
  Ca  Ca12  1  0.202  0.601  0.803  1.0
  Ca  Ca13  1  0.601  0.798  0.399  1.0
  Ta  Ta14  1  0.101  0.303  0.404  1.0
  Ta  Ta15  1  0.500  0.500  0.000  1.0
  Ta  Ta16  1  0.899  0.697  0.596  1.0
  Ta  Ta17  1  0.303  0.899  0.203  1.0
  Ta  Ta18  1  0.697  0.101  0.797  1.0
  Ta  Ta19  1  0.000  0.000  0.000  1.0
  O  O20  1  0.041  0.659  0.701  1.0
  O  O21  1  0.439  0.855  0.294  1.0
  O  O22  1  0.859  0.047  0.906  1.0
  O  O23  1  0.236  0.247  0.483  1.0
  O  O24  1  0.638  0.454  0.092  1.0
  O  O25  1  0.475  0.865  0.805  1.0
  O  O26  1  0.865  0.060  0.390  1.0
  O  O27  1  0.246  0.246  0.000  1.0
  O  O28  1  0.670  0.475  0.610  1.0
  O  O29  1  0.060  0.670  0.195  1.0
  O  O30  1  0.145  0.439  0.583  1.0
  O  O31  1  0.546  0.638  0.184  1.0
  O  O32  1  0.953  0.859  0.812  1.0
  O  O33  1  0.341  0.041  0.382  1.0
  O  O34  1  0.753  0.236  0.989  1.0
  O  O35  1  0.940  0.330  0.805  1.0
  O  O36  1  0.330  0.525  0.390  1.0
  O  O37  1  0.754  0.754  0.000  1.0
  O  O38  1  0.135  0.940  0.610  1.0
  O  O39  1  0.525  0.135  0.195  1.0
  O  O40  1  0.247  0.764  0.011  1.0
  O  O41  1  0.659  0.959  0.618  1.0
  O  O42  1  0.047  0.141  0.188  1.0
  O  O43  1  0.454  0.362  0.816  1.0
  O  O44  1  0.855  0.561  0.417  1.0
  O  O45  1  0.362  0.546  0.908  1.0
  O  O46  1  0.764  0.753  0.517  1.0
  O  O47  1  0.141  0.953  0.094  1.0
  O  O48  1  0.561  0.145  0.706  1.0
  O  O49  1  0.959  0.341  0.299  1.0
[/CIF]
.
The material structure described by Ba5Ca2Ta3O15 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal I4/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(1), one O(2), one O(7), two equivalent O(3), two equivalent O(4), two equivalent O(5), and three equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(2)O12 cuboctahedra, corners with nine equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra, faces with five equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ta(2)O6 octahedra,  a faceface with one Ta(3)O6 octahedra, faces with three equivalent Ca(1)O6 octahedra, and faces with three equivalent Ta(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ca(1)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(6) atoms to form CaO6 octahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with five equivalent Ta(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. There are three inequivalent Ta sites. In the first Ta site, Ta(3) is bonded to two equivalent O(7) and four equivalent O(3) atoms to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with four equivalent Ta(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(3)O6 octahedra, corners with five equivalent Ca(1)O6 octahedra, faces with two equivalent Ba(2)O12 cuboctahedra, and faces with six equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third Ta site, Ta(2) is bonded to two equivalent O(7) and four equivalent O(5) atoms to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Ta(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Ta(1) atom. In the third O site, O(3) is bonded to four equivalent Ba(1), one Ta(1), and one Ta(3) atom to form a mixture of distorted corner and face-sharing OBa4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one Ta(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 Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(1), one Ca(1), and one Ta(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ta(2), and one Ta(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba5Ca2Ta3O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.463
_cell_length_b   10.463
_cell_length_c   10.463
_cell_angle_alpha   99.468
_cell_angle_beta   99.468
_cell_angle_gamma   132.144
_symmetry_Int_Tables_number   1
_cell_volume   776.315
_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  0.654  0.953  0.099  1.0
  Ba  Ba1  1  0.047  0.147  0.701  1.0
  Ba  Ba2  1  0.446  0.346  0.299  1.0
  Ba  Ba3  1  0.853  0.554  0.901  1.0
  Ba  Ba4  1  0.250  0.750  0.500  1.0
  Ba  Ba5  1  0.750  0.250  0.500  1.0
  Ba  Ba6  1  0.147  0.446  0.099  1.0
  Ba  Ba7  1  0.554  0.654  0.701  1.0
  Ba  Ba8  1  0.953  0.853  0.299  1.0
  Ba  Ba9  1  0.346  0.047  0.901  1.0
  Ca  Ca10  1  0.399  0.202  0.601  1.0
  Ca  Ca11  1  0.798  0.399  0.197  1.0
  Ca  Ca12  1  0.202  0.601  0.803  1.0
  Ca  Ca13  1  0.601  0.798  0.399  1.0
  Ta  Ta14  1  0.101  0.303  0.404  1.0
  Ta  Ta15  1  0.500  0.500  0.000  1.0
  Ta  Ta16  1  0.899  0.697  0.596  1.0
  Ta  Ta17  1  0.303  0.899  0.203  1.0
  Ta  Ta18  1  0.697  0.101  0.797  1.0
  Ta  Ta19  1  0.000  0.000  0.000  1.0
  O  O20  1  0.041  0.659  0.701  1.0
  O  O21  1  0.439  0.855  0.294  1.0
  O  O22  1  0.859  0.047  0.906  1.0
  O  O23  1  0.236  0.247  0.483  1.0
  O  O24  1  0.638  0.454  0.092  1.0
  O  O25  1  0.475  0.865  0.805  1.0
  O  O26  1  0.865  0.060  0.390  1.0
  O  O27  1  0.246  0.246  0.000  1.0
  O  O28  1  0.670  0.475  0.610  1.0
  O  O29  1  0.060  0.670  0.195  1.0
  O  O30  1  0.145  0.439  0.583  1.0
  O  O31  1  0.546  0.638  0.184  1.0
  O  O32  1  0.953  0.859  0.812  1.0
  O  O33  1  0.341  0.041  0.382  1.0
  O  O34  1  0.753  0.236  0.989  1.0
  O  O35  1  0.940  0.330  0.805  1.0
  O  O36  1  0.330  0.525  0.390  1.0
  O  O37  1  0.754  0.754  0.000  1.0
  O  O38  1  0.135  0.940  0.610  1.0
  O  O39  1  0.525  0.135  0.195  1.0
  O  O40  1  0.247  0.764  0.011  1.0
  O  O41  1  0.659  0.959  0.618  1.0
  O  O42  1  0.047  0.141  0.188  1.0
  O  O43  1  0.454  0.362  0.816  1.0
  O  O44  1  0.855  0.561  0.417  1.0
  O  O45  1  0.362  0.546  0.908  1.0
  O  O46  1  0.764  0.753  0.517  1.0
  O  O47  1  0.141  0.953  0.094  1.0
  O  O48  1  0.561  0.145  0.706  1.0
  O  O49  1  0.959  0.341  0.299  1.0
[/CIF]
.