The material described by KCaTbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pnnn space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second K site, K(2) is bonded in a 12-coordinate geometry to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form CaO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Tb(1), and one Nb(1) atom. is represented by the CIF file [CIF]
data_KCaTbNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.414
_cell_length_b   8.411
_cell_length_c   8.376
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   592.802
_cell_formula_units_Z   4
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
  K  K0  1  0.000  0.500  0.500  1.0
  K  K1  1  0.500  0.500  0.000  1.0
  K  K2  1  0.500  0.000  0.000  1.0
  K  K3  1  0.000  0.000  0.500  1.0
  Ca  Ca4  1  0.500  0.000  0.500  1.0
  Ca  Ca5  1  0.000  0.500  0.000  1.0
  Ca  Ca6  1  0.000  0.000  0.000  1.0
  Ca  Ca7  1  0.500  0.500  0.500  1.0
  Tb  Tb8  1  0.250  0.250  0.250  1.0
  Tb  Tb9  1  0.750  0.750  0.250  1.0
  Tb  Tb10  1  0.750  0.250  0.750  1.0
  Tb  Tb11  1  0.250  0.750  0.750  1.0
  Nb  Nb12  1  0.750  0.750  0.750  1.0
  Nb  Nb13  1  0.250  0.250  0.750  1.0
  Nb  Nb14  1  0.250  0.750  0.250  1.0
  Nb  Nb15  1  0.750  0.250  0.250  1.0
  O  O16  1  0.985  0.229  0.275  1.0
  O  O17  1  0.015  0.771  0.275  1.0
  O  O18  1  0.015  0.229  0.725  1.0
  O  O19  1  0.985  0.771  0.725  1.0
  O  O20  1  0.260  0.985  0.215  1.0
  O  O21  1  0.260  0.015  0.785  1.0
  O  O22  1  0.740  0.015  0.215  1.0
  O  O23  1  0.740  0.985  0.785  1.0
  O  O24  1  0.199  0.283  0.986  1.0
  O  O25  1  0.801  0.283  0.014  1.0
  O  O26  1  0.199  0.717  0.014  1.0
  O  O27  1  0.801  0.717  0.986  1.0
  O  O28  1  0.515  0.271  0.225  1.0
  O  O29  1  0.485  0.729  0.225  1.0
  O  O30  1  0.485  0.271  0.775  1.0
  O  O31  1  0.515  0.729  0.775  1.0
  O  O32  1  0.240  0.515  0.285  1.0
  O  O33  1  0.240  0.485  0.715  1.0
  O  O34  1  0.760  0.485  0.285  1.0
  O  O35  1  0.760  0.515  0.715  1.0
  O  O36  1  0.301  0.217  0.514  1.0
  O  O37  1  0.699  0.217  0.486  1.0
  O  O38  1  0.301  0.783  0.486  1.0
  O  O39  1  0.699  0.783  0.514  1.0
[/CIF]
.
The material described by KCaTbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pnnn space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second K site, K(2) is bonded in a 12-coordinate geometry to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form CaO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Tb(1), and one Nb(1) atom. is represented by the CIF file [CIF]
data_KCaTbNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.414
_cell_length_b   8.411
_cell_length_c   8.376
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   592.802
_cell_formula_units_Z   4
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
  K  K0  1  0.000  0.500  0.500  1.0
  K  K1  1  0.500  0.500  0.000  1.0
  K  K2  1  0.500  0.000  0.000  1.0
  K  K3  1  0.000  0.000  0.500  1.0
  Ca  Ca4  1  0.500  0.000  0.500  1.0
  Ca  Ca5  1  0.000  0.500  0.000  1.0
  Ca  Ca6  1  0.000  0.000  0.000  1.0
  Ca  Ca7  1  0.500  0.500  0.500  1.0
  Tb  Tb8  1  0.250  0.250  0.250  1.0
  Tb  Tb9  1  0.750  0.750  0.250  1.0
  Tb  Tb10  1  0.750  0.250  0.750  1.0
  Tb  Tb11  1  0.250  0.750  0.750  1.0
  Nb  Nb12  1  0.750  0.750  0.750  1.0
  Nb  Nb13  1  0.250  0.250  0.750  1.0
  Nb  Nb14  1  0.250  0.750  0.250  1.0
  Nb  Nb15  1  0.750  0.250  0.250  1.0
  O  O16  1  0.985  0.229  0.275  1.0
  O  O17  1  0.015  0.771  0.275  1.0
  O  O18  1  0.015  0.229  0.725  1.0
  O  O19  1  0.985  0.771  0.725  1.0
  O  O20  1  0.260  0.985  0.215  1.0
  O  O21  1  0.260  0.015  0.785  1.0
  O  O22  1  0.740  0.015  0.215  1.0
  O  O23  1  0.740  0.985  0.785  1.0
  O  O24  1  0.199  0.283  0.986  1.0
  O  O25  1  0.801  0.283  0.014  1.0
  O  O26  1  0.199  0.717  0.014  1.0
  O  O27  1  0.801  0.717  0.986  1.0
  O  O28  1  0.515  0.271  0.225  1.0
  O  O29  1  0.485  0.729  0.225  1.0
  O  O30  1  0.485  0.271  0.775  1.0
  O  O31  1  0.515  0.729  0.775  1.0
  O  O32  1  0.240  0.515  0.285  1.0
  O  O33  1  0.240  0.485  0.715  1.0
  O  O34  1  0.760  0.485  0.285  1.0
  O  O35  1  0.760  0.515  0.715  1.0
  O  O36  1  0.301  0.217  0.514  1.0
  O  O37  1  0.699  0.217  0.486  1.0
  O  O38  1  0.301  0.783  0.486  1.0
  O  O39  1  0.699  0.783  0.514  1.0
[/CIF]
.