The crystal structure described by Ba3CaBi2O9 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Immm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(1), two equivalent O(2), four equivalent O(3), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with ten equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ca(1)O6 octahedra, faces with two equivalent Bi(1)O6 octahedra, faces with two equivalent Bi(2)O6 octahedra, and faces with two equivalent Bi(3)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(1), two equivalent O(3), two equivalent O(5), three equivalent O(2), and four equivalent O(4) atoms to form BaO12 cuboctahedra that share corners with five equivalent Ba(1)O12 cuboctahedra, corners with seven equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Bi(1)O6 octahedra,  a faceface with one Bi(3)O6 octahedra, faces with three equivalent Ca(1)O6 octahedra, and faces with three equivalent Bi(2)O6 octahedra. Ca(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Bi(2)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-6°. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(1) and four equivalent O(5) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Bi site, Bi(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-6°. In the third Bi site, Bi(3) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Bi(2)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are five 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 Bi(1), and one Bi(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Ca(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(4) is bonded to four equivalent Ba(2), one Ca(1), and one Bi(2) atom to form a mixture of distorted edge, corner, and face-sharing OBa4CaBi octahedra. The corner-sharing octahedral tilt angles are 58°. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Bi(1) atom. is represented by the CIF file [CIF]
data_Ba3CaBi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.694
_cell_length_b   10.694
_cell_length_c   10.694
_cell_angle_alpha   146.478
_cell_angle_beta   131.952
_cell_angle_gamma   59.856
_symmetry_Int_Tables_number   1
_cell_volume   497.806
_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  0.758  0.500  0.258  1.0
  Ba  Ba1  1  0.417  0.170  0.247  1.0
  Ba  Ba2  1  0.078  0.830  0.247  1.0
  Ba  Ba3  1  0.242  0.500  0.742  1.0
  Ba  Ba4  1  0.922  0.170  0.753  1.0
  Ba  Ba5  1  0.583  0.830  0.753  1.0
  Ca  Ca6  1  0.166  0.666  0.500  1.0
  Ca  Ca7  1  0.834  0.334  0.500  1.0
  Bi  Bi8  1  0.000  0.000  0.000  1.0
  Bi  Bi9  1  0.668  0.668  0.000  1.0
  Bi  Bi10  1  0.332  0.332  0.000  1.0
  Bi  Bi11  1  0.500  0.000  0.500  1.0
  O  O12  1  0.745  0.000  0.745  1.0
  O  O13  1  0.423  0.661  0.762  1.0
  O  O14  1  0.101  0.339  0.762  1.0
  O  O15  1  0.581  0.834  0.253  1.0
  O  O16  1  0.254  0.500  0.245  1.0
  O  O17  1  0.921  0.160  0.240  1.0
  O  O18  1  0.419  0.672  0.253  1.0
  O  O19  1  0.079  0.319  0.240  1.0
  O  O20  1  0.746  0.991  0.245  1.0
  O  O21  1  0.255  0.000  0.255  1.0
  O  O22  1  0.899  0.661  0.238  1.0
  O  O23  1  0.577  0.339  0.238  1.0
  O  O24  1  0.419  0.166  0.747  1.0
  O  O25  1  0.079  0.840  0.760  1.0
  O  O26  1  0.746  0.500  0.755  1.0
  O  O27  1  0.581  0.328  0.747  1.0
  O  O28  1  0.254  0.009  0.755  1.0
  O  O29  1  0.921  0.681  0.760  1.0
[/CIF]
.
The crystal structure described by Ba3CaBi2O9 is (Cubic) Perovskite-derived structured and crystallizes in the orthorhombic Immm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(1), two equivalent O(2), four equivalent O(3), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with ten equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ca(1)O6 octahedra, faces with two equivalent Bi(1)O6 octahedra, faces with two equivalent Bi(2)O6 octahedra, and faces with two equivalent Bi(3)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(1), two equivalent O(3), two equivalent O(5), three equivalent O(2), and four equivalent O(4) atoms to form BaO12 cuboctahedra that share corners with five equivalent Ba(1)O12 cuboctahedra, corners with seven equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Bi(1)O6 octahedra,  a faceface with one Bi(3)O6 octahedra, faces with three equivalent Ca(1)O6 octahedra, and faces with three equivalent Bi(2)O6 octahedra. Ca(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Bi(2)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-6°. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(1) and four equivalent O(5) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Bi site, Bi(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-6°. In the third Bi site, Bi(3) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Bi(2)O6 octahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are five 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 Bi(1), and one Bi(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Ca(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Bi(2), and one Bi(3) atom. In the fourth O site, O(4) is bonded to four equivalent Ba(2), one Ca(1), and one Bi(2) atom to form a mixture of distorted edge, corner, and face-sharing OBa4CaBi octahedra. The corner-sharing octahedral tilt angles are 58°. In the fifth O site, O(5) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Ca(1), and one Bi(1) atom. is represented by the CIF file [CIF]
data_Ba3CaBi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.694
_cell_length_b   10.694
_cell_length_c   10.694
_cell_angle_alpha   146.478
_cell_angle_beta   131.952
_cell_angle_gamma   59.856
_symmetry_Int_Tables_number   1
_cell_volume   497.806
_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  0.758  0.500  0.258  1.0
  Ba  Ba1  1  0.417  0.170  0.247  1.0
  Ba  Ba2  1  0.078  0.830  0.247  1.0
  Ba  Ba3  1  0.242  0.500  0.742  1.0
  Ba  Ba4  1  0.922  0.170  0.753  1.0
  Ba  Ba5  1  0.583  0.830  0.753  1.0
  Ca  Ca6  1  0.166  0.666  0.500  1.0
  Ca  Ca7  1  0.834  0.334  0.500  1.0
  Bi  Bi8  1  0.000  0.000  0.000  1.0
  Bi  Bi9  1  0.668  0.668  0.000  1.0
  Bi  Bi10  1  0.332  0.332  0.000  1.0
  Bi  Bi11  1  0.500  0.000  0.500  1.0
  O  O12  1  0.745  0.000  0.745  1.0
  O  O13  1  0.423  0.661  0.762  1.0
  O  O14  1  0.101  0.339  0.762  1.0
  O  O15  1  0.581  0.834  0.253  1.0
  O  O16  1  0.254  0.500  0.245  1.0
  O  O17  1  0.921  0.160  0.240  1.0
  O  O18  1  0.419  0.672  0.253  1.0
  O  O19  1  0.079  0.319  0.240  1.0
  O  O20  1  0.746  0.991  0.245  1.0
  O  O21  1  0.255  0.000  0.255  1.0
  O  O22  1  0.899  0.661  0.238  1.0
  O  O23  1  0.577  0.339  0.238  1.0
  O  O24  1  0.419  0.166  0.747  1.0
  O  O25  1  0.079  0.840  0.760  1.0
  O  O26  1  0.746  0.500  0.755  1.0
  O  O27  1  0.581  0.328  0.747  1.0
  O  O28  1  0.254  0.009  0.755  1.0
  O  O29  1  0.921  0.681  0.760  1.0
[/CIF]
.