The structure described by CrTa2O6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Cr(2)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-51°. In the second Ta site, Ta(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-53°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share corners with eight equivalent Ta(2)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with eight equivalent Ta(1)O6 octahedra and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ta(1) and one Cr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to two equivalent Ta(2) and one Cr(1) atom. is represented by the CIF file [CIF]
data_Ta2CrO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.837
_cell_length_b   4.837
_cell_length_c   9.237
_cell_angle_alpha   89.286
_cell_angle_beta   89.288
_cell_angle_gamma   89.884
_symmetry_Int_Tables_number   1
_cell_volume   216.072
_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
  Ta  Ta0  1  0.498  0.498  0.167  1.0
  Ta  Ta1  1  0.004  0.004  0.671  1.0
  Ta  Ta2  1  0.502  0.502  0.833  1.0
  Ta  Ta3  1  0.996  0.996  0.328  1.0
  Cr  Cr4  1  0.500  0.500  0.500  1.0
  Cr  Cr5  1  1.000  0.000  1.000  1.0
  O  O6  1  0.282  0.282  0.312  1.0
  O  O7  1  0.214  0.801  0.824  1.0
  O  O8  1  0.801  0.214  0.824  1.0
  O  O9  1  0.786  0.199  0.176  1.0
  O  O10  1  0.199  0.786  0.176  1.0
  O  O11  1  0.697  0.697  0.323  1.0
  O  O12  1  0.303  0.303  0.677  1.0
  O  O13  1  0.718  0.718  0.688  1.0
  O  O14  1  0.312  0.312  0.999  1.0
  O  O15  1  0.186  0.814  0.500  1.0
  O  O16  1  0.814  0.186  0.500  1.0
  O  O17  1  0.688  0.688  0.001  1.0
[/CIF]
.
The structure described by CrTa2O6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Cr(2)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-51°. In the second Ta site, Ta(2) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-53°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share corners with eight equivalent Ta(2)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with eight equivalent Ta(1)O6 octahedra and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(2), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ta(1) and one Cr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to two equivalent Ta(2) and one Cr(1) atom. is represented by the CIF file [CIF]
data_Ta2CrO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.837
_cell_length_b   4.837
_cell_length_c   9.237
_cell_angle_alpha   89.286
_cell_angle_beta   89.288
_cell_angle_gamma   89.884
_symmetry_Int_Tables_number   1
_cell_volume   216.072
_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
  Ta  Ta0  1  0.498  0.498  0.167  1.0
  Ta  Ta1  1  0.004  0.004  0.671  1.0
  Ta  Ta2  1  0.502  0.502  0.833  1.0
  Ta  Ta3  1  0.996  0.996  0.328  1.0
  Cr  Cr4  1  0.500  0.500  0.500  1.0
  Cr  Cr5  1  1.000  0.000  1.000  1.0
  O  O6  1  0.282  0.282  0.312  1.0
  O  O7  1  0.214  0.801  0.824  1.0
  O  O8  1  0.801  0.214  0.824  1.0
  O  O9  1  0.786  0.199  0.176  1.0
  O  O10  1  0.199  0.786  0.176  1.0
  O  O11  1  0.697  0.697  0.323  1.0
  O  O12  1  0.303  0.303  0.677  1.0
  O  O13  1  0.718  0.718  0.688  1.0
  O  O14  1  0.312  0.312  0.999  1.0
  O  O15  1  0.186  0.814  0.500  1.0
  O  O16  1  0.814  0.186  0.500  1.0
  O  O17  1  0.688  0.688  0.001  1.0
[/CIF]
.