The structure described by Ca3W2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. W(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 32-35°. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(2) and one W(1) atom to form OCa3W tetrahedra that share  a cornercorner with one O(4)Ca2W2 tetrahedra, corners with six equivalent O(1)Ca3W tetrahedra,  a cornercorner with one O(3)Ca3W2 trigonal bipyramid, and edges with two equivalent O(3)Ca3W2 trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent W(1) atoms. In the third O site, O(3) is bonded to one Ca(2), two equivalent Ca(1), and two equivalent W(1) atoms to form distorted OCa3W2 trigonal bipyramids that share  a cornercorner with one O(1)Ca3W tetrahedra, corners with four equivalent O(4)Ca2W2 tetrahedra, corners with two equivalent O(3)Ca3W2 trigonal bipyramids,  an edgeedge with one O(4)Ca2W2 tetrahedra, edges with two equivalent O(1)Ca3W tetrahedra, and edges with three equivalent O(3)Ca3W2 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent W(1) atoms to form OCa2W2 tetrahedra that share corners with two equivalent O(4)Ca2W2 tetrahedra, corners with two equivalent O(1)Ca3W tetrahedra, corners with eight equivalent O(3)Ca3W2 trigonal bipyramids, and edges with two equivalent O(3)Ca3W2 trigonal bipyramids. is represented by the CIF card [CIF]
data_Ca3W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.274
_cell_length_b   10.274
_cell_length_c   5.793
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   148.030
_symmetry_Int_Tables_number   1
_cell_volume   323.725
_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  0.243  0.243  0.301  1.0
  Ca  Ca1  1  0.757  0.757  0.801  1.0
  Ca  Ca2  1  0.046  0.427  0.196  1.0
  Ca  Ca3  1  0.954  0.573  0.696  1.0
  Ca  Ca4  1  0.427  0.046  0.196  1.0
  Ca  Ca5  1  0.573  0.954  0.696  1.0
  W  W6  1  0.850  0.648  0.251  1.0
  W  W7  1  0.150  0.352  0.751  1.0
  W  W8  1  0.352  0.150  0.751  1.0
  W  W9  1  0.648  0.850  0.251  1.0
  O  O10  1  0.638  0.040  0.286  1.0
  O  O11  1  0.362  0.960  0.786  1.0
  O  O12  1  0.960  0.362  0.786  1.0
  O  O13  1  0.040  0.638  0.286  1.0
  O  O14  1  0.432  0.671  0.942  1.0
  O  O15  1  0.568  0.329  0.442  1.0
  O  O16  1  0.329  0.568  0.442  1.0
  O  O17  1  0.671  0.432  0.942  1.0
  O  O18  1  0.969  0.130  0.060  1.0
  O  O19  1  0.031  0.870  0.560  1.0
  O  O20  1  0.648  0.648  0.208  1.0
  O  O21  1  0.352  0.352  0.708  1.0
  O  O22  1  0.130  0.969  0.060  1.0
  O  O23  1  0.870  0.031  0.560  1.0
[/CIF]
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The structure described by Ca3W2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(1) atoms. W(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 32-35°. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(2) and one W(1) atom to form OCa3W tetrahedra that share  a cornercorner with one O(4)Ca2W2 tetrahedra, corners with six equivalent O(1)Ca3W tetrahedra,  a cornercorner with one O(3)Ca3W2 trigonal bipyramid, and edges with two equivalent O(3)Ca3W2 trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent W(1) atoms. In the third O site, O(3) is bonded to one Ca(2), two equivalent Ca(1), and two equivalent W(1) atoms to form distorted OCa3W2 trigonal bipyramids that share  a cornercorner with one O(1)Ca3W tetrahedra, corners with four equivalent O(4)Ca2W2 tetrahedra, corners with two equivalent O(3)Ca3W2 trigonal bipyramids,  an edgeedge with one O(4)Ca2W2 tetrahedra, edges with two equivalent O(1)Ca3W tetrahedra, and edges with three equivalent O(3)Ca3W2 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent W(1) atoms to form OCa2W2 tetrahedra that share corners with two equivalent O(4)Ca2W2 tetrahedra, corners with two equivalent O(1)Ca3W tetrahedra, corners with eight equivalent O(3)Ca3W2 trigonal bipyramids, and edges with two equivalent O(3)Ca3W2 trigonal bipyramids. is represented by the CIF card [CIF]
data_Ca3W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.274
_cell_length_b   10.274
_cell_length_c   5.793
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   148.030
_symmetry_Int_Tables_number   1
_cell_volume   323.725
_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  0.243  0.243  0.301  1.0
  Ca  Ca1  1  0.757  0.757  0.801  1.0
  Ca  Ca2  1  0.046  0.427  0.196  1.0
  Ca  Ca3  1  0.954  0.573  0.696  1.0
  Ca  Ca4  1  0.427  0.046  0.196  1.0
  Ca  Ca5  1  0.573  0.954  0.696  1.0
  W  W6  1  0.850  0.648  0.251  1.0
  W  W7  1  0.150  0.352  0.751  1.0
  W  W8  1  0.352  0.150  0.751  1.0
  W  W9  1  0.648  0.850  0.251  1.0
  O  O10  1  0.638  0.040  0.286  1.0
  O  O11  1  0.362  0.960  0.786  1.0
  O  O12  1  0.960  0.362  0.786  1.0
  O  O13  1  0.040  0.638  0.286  1.0
  O  O14  1  0.432  0.671  0.942  1.0
  O  O15  1  0.568  0.329  0.442  1.0
  O  O16  1  0.329  0.568  0.442  1.0
  O  O17  1  0.671  0.432  0.942  1.0
  O  O18  1  0.969  0.130  0.060  1.0
  O  O19  1  0.031  0.870  0.560  1.0
  O  O20  1  0.648  0.648  0.208  1.0
  O  O21  1  0.352  0.352  0.708  1.0
  O  O22  1  0.130  0.969  0.060  1.0
  O  O23  1  0.870  0.031  0.560  1.0
[/CIF]
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