The material described by BaCaNb4O12 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with eight equivalent Ca(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Ca(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(1)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-5°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(1), one Ca(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), one Ca(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted square co-planar geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ca(1) and two equivalent Nb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaCaNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.694
_cell_length_b   5.694
_cell_length_c   8.045
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   89.944
_symmetry_Int_Tables_number   1
_cell_volume   260.784
_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  0.500  0.000  1.0
  Ca  Ca1  1  0.000  0.000  0.500  1.0
  Nb  Nb2  1  0.000  0.500  0.253  1.0
  Nb  Nb3  1  0.000  0.500  0.747  1.0
  Nb  Nb4  1  0.500  0.000  0.253  1.0
  Nb  Nb5  1  0.500  0.000  0.747  1.0
  O  O6  1  0.255  0.255  0.255  1.0
  O  O7  1  0.255  0.255  0.745  1.0
  O  O8  1  0.745  0.745  0.255  1.0
  O  O9  1  0.745  0.745  0.745  1.0
  O  O10  1  0.761  0.239  0.743  1.0
  O  O11  1  0.761  0.239  0.257  1.0
  O  O12  1  0.239  0.761  0.257  1.0
  O  O13  1  0.239  0.761  0.743  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.500  0.000  0.000  1.0
  O  O17  1  0.500  0.000  0.500  1.0
[/CIF]
.
The material described by BaCaNb4O12 crystallizes in the orthorhombic Cmmm space group. Ba(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with eight equivalent Ca(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Ca(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(1)O12 cuboctahedra, corners with eight equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with two equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-5°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(1), one Ca(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Ba(1), one Ca(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted square co-planar geometry to two equivalent Ba(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Ca(1) and two equivalent Nb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaCaNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.694
_cell_length_b   5.694
_cell_length_c   8.045
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   89.944
_symmetry_Int_Tables_number   1
_cell_volume   260.784
_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  0.500  0.000  1.0
  Ca  Ca1  1  0.000  0.000  0.500  1.0
  Nb  Nb2  1  0.000  0.500  0.253  1.0
  Nb  Nb3  1  0.000  0.500  0.747  1.0
  Nb  Nb4  1  0.500  0.000  0.253  1.0
  Nb  Nb5  1  0.500  0.000  0.747  1.0
  O  O6  1  0.255  0.255  0.255  1.0
  O  O7  1  0.255  0.255  0.745  1.0
  O  O8  1  0.745  0.745  0.255  1.0
  O  O9  1  0.745  0.745  0.745  1.0
  O  O10  1  0.761  0.239  0.743  1.0
  O  O11  1  0.761  0.239  0.257  1.0
  O  O12  1  0.239  0.761  0.257  1.0
  O  O13  1  0.239  0.761  0.743  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.500  0.000  0.000  1.0
  O  O17  1  0.500  0.000  0.500  1.0
[/CIF]
.