The structure described by Ca2Ta2VO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(4), and four equivalent O(3) atoms. Ta(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted TaO6 octahedra that share corners with four equivalent V(1)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. V(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form VO6 octahedra that share corners with eight equivalent Ta(1)O6 octahedra and edges with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. There are four inequivalent O sites. In the first O site, O(4) is bonded to three equivalent Ca(1) and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OCa3Ta trigonal pyramids. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), two equivalent Ta(1), and one V(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent V(1) atoms. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ca2Ta2VO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.527
_cell_length_b   6.336
_cell_length_c   10.069
_cell_angle_alpha   108.329
_cell_angle_beta   91.427
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   334.618
_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  0.245  0.888  0.417  1.0
  Ca  Ca1  1  0.258  0.472  0.583  1.0
  Ca  Ca2  1  0.758  0.110  0.583  1.0
  Ca  Ca3  1  0.745  0.527  0.417  1.0
  O  O4  1  0.909  0.054  0.858  1.0
  O  O5  1  0.593  0.196  0.142  1.0
  O  O6  1  0.093  0.945  0.142  1.0
  O  O7  1  0.409  0.803  0.858  1.0
  O  O8  1  0.404  0.296  0.885  1.0
  O  O9  1  0.098  0.410  0.115  1.0
  O  O10  1  0.598  0.703  0.115  1.0
  O  O11  1  0.904  0.588  0.885  1.0
  O  O12  1  0.499  0.880  0.638  1.0
  O  O13  1  0.004  0.242  0.362  1.0
  O  O14  1  0.999  0.756  0.638  1.0
  O  O15  1  0.504  0.118  0.362  1.0
  O  O16  1  0.656  0.466  0.630  1.0
  O  O17  1  0.846  0.837  0.370  1.0
  O  O18  1  0.346  0.532  0.371  1.0
  O  O19  1  0.156  0.162  0.630  1.0
  Ta  Ta20  1  0.242  0.036  0.776  1.0
  Ta  Ta21  1  0.260  0.261  0.225  1.0
  Ta  Ta22  1  0.760  0.962  0.225  1.0
  Ta  Ta23  1  0.742  0.738  0.776  1.0
  V  V24  1  0.251  0.633  0.000  1.0
  V  V25  1  0.751  0.365  0.000  1.0
[/CIF]
.
The structure described by Ca2Ta2VO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(4), and four equivalent O(3) atoms. Ta(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted TaO6 octahedra that share corners with four equivalent V(1)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. V(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form VO6 octahedra that share corners with eight equivalent Ta(1)O6 octahedra and edges with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. There are four inequivalent O sites. In the first O site, O(4) is bonded to three equivalent Ca(1) and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OCa3Ta trigonal pyramids. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), two equivalent Ta(1), and one V(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent V(1) atoms. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ca2Ta2VO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.527
_cell_length_b   6.336
_cell_length_c   10.069
_cell_angle_alpha   108.329
_cell_angle_beta   91.427
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   334.618
_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  0.245  0.888  0.417  1.0
  Ca  Ca1  1  0.258  0.472  0.583  1.0
  Ca  Ca2  1  0.758  0.110  0.583  1.0
  Ca  Ca3  1  0.745  0.527  0.417  1.0
  O  O4  1  0.909  0.054  0.858  1.0
  O  O5  1  0.593  0.196  0.142  1.0
  O  O6  1  0.093  0.945  0.142  1.0
  O  O7  1  0.409  0.803  0.858  1.0
  O  O8  1  0.404  0.296  0.885  1.0
  O  O9  1  0.098  0.410  0.115  1.0
  O  O10  1  0.598  0.703  0.115  1.0
  O  O11  1  0.904  0.588  0.885  1.0
  O  O12  1  0.499  0.880  0.638  1.0
  O  O13  1  0.004  0.242  0.362  1.0
  O  O14  1  0.999  0.756  0.638  1.0
  O  O15  1  0.504  0.118  0.362  1.0
  O  O16  1  0.656  0.466  0.630  1.0
  O  O17  1  0.846  0.837  0.370  1.0
  O  O18  1  0.346  0.532  0.371  1.0
  O  O19  1  0.156  0.162  0.630  1.0
  Ta  Ta20  1  0.242  0.036  0.776  1.0
  Ta  Ta21  1  0.260  0.261  0.225  1.0
  Ta  Ta22  1  0.760  0.962  0.225  1.0
  Ta  Ta23  1  0.742  0.738  0.776  1.0
  V  V24  1  0.251  0.633  0.000  1.0
  V  V25  1  0.751  0.365  0.000  1.0
[/CIF]
.