The compound described by BaCa2Y6O12 crystallizes in the hexagonal P-6 space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(1) and six equivalent O(2) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to six equivalent O(4) atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent Y(1)O6 octahedra, corners with six equivalent Y(2)O6 octahedra, edges with three equivalent Y(1)O6 octahedra, and faces with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 23-77°. In the second Ca site, Ca(2) is bonded to six equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent Y(1)O6 octahedra, corners with six equivalent Y(2)O6 octahedra, edges with three equivalent Y(2)O6 octahedra, and faces with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 22-76°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form YO6 octahedra that share corners with four equivalent Y(2)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(2)O6 pentagonal pyramids, edges with two equivalent Y(1)O6 octahedra, edges with two equivalent Y(2)O6 octahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 55-59°. In the second Y site, Y(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Y(1)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(2)O6 pentagonal pyramids, edges with two equivalent Y(1)O6 octahedra, edges with two equivalent Y(2)O6 octahedra, and  an edgeedge with one Ca(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 55-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Y(1), and two equivalent Y(2) atoms to form distorted OBaY3 tetrahedra that share corners with three equivalent O(3)Ca2Y3 square pyramids, corners with four equivalent O(4)Ca2Y3 square pyramids, corners with four equivalent O(1)BaY3 tetrahedra, and  an edgeedge with one O(3)Ca2Y3 square pyramid. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ba(1), one Y(2), and two equivalent Y(1) atoms. In the third O site, O(3) is bonded to two equivalent Ca(2), one Y(1), and two equivalent Y(2) atoms to form OCa2Y3 square pyramids that share corners with four equivalent O(3)Ca2Y3 square pyramids, corners with three equivalent O(1)BaY3 tetrahedra, edges with two equivalent O(4)Ca2Y3 square pyramids, edges with four equivalent O(3)Ca2Y3 square pyramids, and  an edgeedge with one O(1)BaY3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Y(2), and two equivalent Y(1) atoms to form distorted OCa2Y3 square pyramids that share corners with four equivalent O(4)Ca2Y3 square pyramids, corners with four equivalent O(1)BaY3 tetrahedra, edges with two equivalent O(3)Ca2Y3 square pyramids, and edges with four equivalent O(4)Ca2Y3 square pyramids. is represented by the CIF file [CIF]
data_BaCa2Y6O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.410
_cell_length_b   10.323
_cell_length_c   10.323
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.680
_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  0.750  0.000  0.000  1.0
  Ca  Ca1  1  0.750  0.667  0.333  1.0
  Ca  Ca2  1  0.250  0.333  0.667  1.0
  Y  Y3  1  0.750  0.350  0.001  1.0
  Y  Y4  1  0.750  0.999  0.348  1.0
  Y  Y5  1  0.750  0.652  0.650  1.0
  Y  Y6  1  0.250  0.653  0.999  1.0
  Y  Y7  1  0.250  0.001  0.654  1.0
  Y  Y8  1  0.250  0.346  0.347  1.0
  O  O9  1  0.750  0.890  0.696  1.0
  O  O10  1  0.750  0.304  0.193  1.0
  O  O11  1  0.750  0.807  0.110  1.0
  O  O12  1  0.250  0.099  0.281  1.0
  O  O13  1  0.250  0.719  0.818  1.0
  O  O14  1  0.250  0.182  0.901  1.0
  O  O15  1  0.750  0.136  0.608  1.0
  O  O16  1  0.750  0.392  0.529  1.0
  O  O17  1  0.750  0.471  0.864  1.0
  O  O18  1  0.250  0.867  0.395  1.0
  O  O19  1  0.250  0.605  0.472  1.0
  O  O20  1  0.250  0.528  0.133  1.0
[/CIF]
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The compound described by BaCa2Y6O12 crystallizes in the hexagonal P-6 space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent O(1) and six equivalent O(2) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to six equivalent O(4) atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent Y(1)O6 octahedra, corners with six equivalent Y(2)O6 octahedra, edges with three equivalent Y(1)O6 octahedra, and faces with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 23-77°. In the second Ca site, Ca(2) is bonded to six equivalent O(3) atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent Y(1)O6 octahedra, corners with six equivalent Y(2)O6 octahedra, edges with three equivalent Y(2)O6 octahedra, and faces with two equivalent Ca(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 22-76°. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form YO6 octahedra that share corners with four equivalent Y(2)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(2)O6 pentagonal pyramids, edges with two equivalent Y(1)O6 octahedra, edges with two equivalent Y(2)O6 octahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 55-59°. In the second Y site, Y(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form YO6 octahedra that share corners with four equivalent Y(1)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with two equivalent Ca(2)O6 pentagonal pyramids, edges with two equivalent Y(1)O6 octahedra, edges with two equivalent Y(2)O6 octahedra, and  an edgeedge with one Ca(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 55-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Y(1), and two equivalent Y(2) atoms to form distorted OBaY3 tetrahedra that share corners with three equivalent O(3)Ca2Y3 square pyramids, corners with four equivalent O(4)Ca2Y3 square pyramids, corners with four equivalent O(1)BaY3 tetrahedra, and  an edgeedge with one O(3)Ca2Y3 square pyramid. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ba(1), one Y(2), and two equivalent Y(1) atoms. In the third O site, O(3) is bonded to two equivalent Ca(2), one Y(1), and two equivalent Y(2) atoms to form OCa2Y3 square pyramids that share corners with four equivalent O(3)Ca2Y3 square pyramids, corners with three equivalent O(1)BaY3 tetrahedra, edges with two equivalent O(4)Ca2Y3 square pyramids, edges with four equivalent O(3)Ca2Y3 square pyramids, and  an edgeedge with one O(1)BaY3 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Y(2), and two equivalent Y(1) atoms to form distorted OCa2Y3 square pyramids that share corners with four equivalent O(4)Ca2Y3 square pyramids, corners with four equivalent O(1)BaY3 tetrahedra, edges with two equivalent O(3)Ca2Y3 square pyramids, and edges with four equivalent O(4)Ca2Y3 square pyramids. is represented by the CIF file [CIF]
data_BaCa2Y6O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.410
_cell_length_b   10.323
_cell_length_c   10.323
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.680
_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  0.750  0.000  0.000  1.0
  Ca  Ca1  1  0.750  0.667  0.333  1.0
  Ca  Ca2  1  0.250  0.333  0.667  1.0
  Y  Y3  1  0.750  0.350  0.001  1.0
  Y  Y4  1  0.750  0.999  0.348  1.0
  Y  Y5  1  0.750  0.652  0.650  1.0
  Y  Y6  1  0.250  0.653  0.999  1.0
  Y  Y7  1  0.250  0.001  0.654  1.0
  Y  Y8  1  0.250  0.346  0.347  1.0
  O  O9  1  0.750  0.890  0.696  1.0
  O  O10  1  0.750  0.304  0.193  1.0
  O  O11  1  0.750  0.807  0.110  1.0
  O  O12  1  0.250  0.099  0.281  1.0
  O  O13  1  0.250  0.719  0.818  1.0
  O  O14  1  0.250  0.182  0.901  1.0
  O  O15  1  0.750  0.136  0.608  1.0
  O  O16  1  0.750  0.392  0.529  1.0
  O  O17  1  0.750  0.471  0.864  1.0
  O  O18  1  0.250  0.867  0.395  1.0
  O  O19  1  0.250  0.605  0.472  1.0
  O  O20  1  0.250  0.528  0.133  1.0
[/CIF]
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