The crystal structure described by Ca2Nb2WO8 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 4-coordinate geometry to one O(12), one O(13), one O(14), one O(15), and one O(16) atom. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to one O(11), one O(13), one O(14), one O(15), and one O(4) atom. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(1), one O(11), one O(12), one O(14), one O(15), and one O(9) atom. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(15), and one O(2) atom. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(14), one O(15), one O(4), one O(5), and one O(9) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Nb site, Nb(2) is bonded to one O(10), one O(13), one O(16), one O(2), one O(3), and one O(6) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the third Nb site, Nb(3) is bonded to one O(10), one O(12), one O(16), one O(2), one O(3), and one O(7) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(11), one O(15), one O(4), one O(8), and one O(9) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and edges with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second W site, W(2) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(3), one Nb(1), one Nb(4), and one W(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(4), one Nb(2), one Nb(3), and one W(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(2), one Nb(3), and one W(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), one Nb(1), one Nb(4), and one W(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Nb(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Nb(2), one W(1), and one W(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Nb(3), one W(1), and one W(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Nb(4), one W(1), and one W(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(3), one Nb(1), and one Nb(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(4), one Nb(2), and one Nb(3) atom. In the eleventh O site, O(11) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Nb(4) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the twelfth O site, O(12) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Nb(3) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Nb(2) atom to form a mixture of distorted edge and corner-sharing OCa3Nb trigonal pyramids. In the fourteenth O site, O(14) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one Nb(1), and one Nb(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ca(1), one Nb(2), and one Nb(3) atom. is represented by the CIF card [CIF]
data_Ca2Nb2WO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.627
_cell_length_b   6.331
_cell_length_c   10.084
_cell_angle_alpha   108.022
_cell_angle_beta   92.364
_cell_angle_gamma   90.393
_symmetry_Int_Tables_number   1
_cell_volume   341.256
_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
  Ca  Ca0  1  0.234  0.887  0.416  1.0
  Ca  Ca1  1  0.268  0.474  0.592  1.0
  Ca  Ca2  1  0.765  0.113  0.592  1.0
  Ca  Ca3  1  0.737  0.519  0.411  1.0
  Nb  Nb4  1  0.236  0.022  0.774  1.0
  Nb  Nb5  1  0.262  0.257  0.228  1.0
  Nb  Nb6  1  0.760  0.968  0.229  1.0
  Nb  Nb7  1  0.751  0.741  0.769  1.0
  W  W8  1  0.248  0.634  0.001  1.0
  W  W9  1  0.745  0.366  0.999  1.0
  O  O10  1  0.897  0.075  0.854  1.0
  O  O11  1  0.592  0.204  0.140  1.0
  O  O12  1  0.091  0.936  0.137  1.0
  O  O13  1  0.404  0.798  0.860  1.0
  O  O14  1  0.399  0.308  0.888  1.0
  O  O15  1  0.090  0.422  0.112  1.0
  O  O16  1  0.592  0.687  0.113  1.0
  O  O17  1  0.905  0.577  0.887  1.0
  O  O18  1  0.512  0.882  0.644  1.0
  O  O19  1  0.986  0.235  0.354  1.0
  O  O20  1  0.664  0.462  0.623  1.0
  O  O21  1  0.833  0.840  0.376  1.0
  O  O22  1  0.336  0.532  0.375  1.0
  O  O23  1  0.164  0.156  0.626  1.0
  O  O24  1  0.010  0.757  0.635  1.0
  O  O25  1  0.486  0.116  0.356  1.0
[/CIF]
.
The crystal structure described by Ca2Nb2WO8 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 4-coordinate geometry to one O(12), one O(13), one O(14), one O(15), and one O(16) atom. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to one O(11), one O(13), one O(14), one O(15), and one O(4) atom. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(1), one O(11), one O(12), one O(14), one O(15), and one O(9) atom. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(15), and one O(2) atom. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(14), one O(15), one O(4), one O(5), and one O(9) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Nb site, Nb(2) is bonded to one O(10), one O(13), one O(16), one O(2), one O(3), and one O(6) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the third Nb site, Nb(3) is bonded to one O(10), one O(12), one O(16), one O(2), one O(3), and one O(7) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the fourth Nb site, Nb(4) is bonded to one O(1), one O(11), one O(15), one O(4), one O(8), and one O(9) atom to form distorted NbO6 octahedra that share corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and edges with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second W site, W(2) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form WO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(3), one Nb(1), one Nb(4), and one W(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(4), one Nb(2), one Nb(3), and one W(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Nb(2), one Nb(3), and one W(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), one Nb(1), one Nb(4), and one W(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Nb(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Nb(2), one W(1), and one W(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Nb(3), one W(1), and one W(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Nb(4), one W(1), and one W(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(3), one Nb(1), and one Nb(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(4), one Nb(2), and one Nb(3) atom. In the eleventh O site, O(11) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Nb(4) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the twelfth O site, O(12) is bonded to one Ca(1), one Ca(3), one Ca(4), and one Nb(3) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Nb(2) atom to form a mixture of distorted edge and corner-sharing OCa3Nb trigonal pyramids. In the fourteenth O site, O(14) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing OCa3Nb tetrahedra. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one Nb(1), and one Nb(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ca(1), one Nb(2), and one Nb(3) atom. is represented by the CIF card [CIF]
data_Ca2Nb2WO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.627
_cell_length_b   6.331
_cell_length_c   10.084
_cell_angle_alpha   108.022
_cell_angle_beta   92.364
_cell_angle_gamma   90.393
_symmetry_Int_Tables_number   1
_cell_volume   341.256
_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
  Ca  Ca0  1  0.234  0.887  0.416  1.0
  Ca  Ca1  1  0.268  0.474  0.592  1.0
  Ca  Ca2  1  0.765  0.113  0.592  1.0
  Ca  Ca3  1  0.737  0.519  0.411  1.0
  Nb  Nb4  1  0.236  0.022  0.774  1.0
  Nb  Nb5  1  0.262  0.257  0.228  1.0
  Nb  Nb6  1  0.760  0.968  0.229  1.0
  Nb  Nb7  1  0.751  0.741  0.769  1.0
  W  W8  1  0.248  0.634  0.001  1.0
  W  W9  1  0.745  0.366  0.999  1.0
  O  O10  1  0.897  0.075  0.854  1.0
  O  O11  1  0.592  0.204  0.140  1.0
  O  O12  1  0.091  0.936  0.137  1.0
  O  O13  1  0.404  0.798  0.860  1.0
  O  O14  1  0.399  0.308  0.888  1.0
  O  O15  1  0.090  0.422  0.112  1.0
  O  O16  1  0.592  0.687  0.113  1.0
  O  O17  1  0.905  0.577  0.887  1.0
  O  O18  1  0.512  0.882  0.644  1.0
  O  O19  1  0.986  0.235  0.354  1.0
  O  O20  1  0.664  0.462  0.623  1.0
  O  O21  1  0.833  0.840  0.376  1.0
  O  O22  1  0.336  0.532  0.375  1.0
  O  O23  1  0.164  0.156  0.626  1.0
  O  O24  1  0.010  0.757  0.635  1.0
  O  O25  1  0.486  0.116  0.356  1.0
[/CIF]
.