The material structure described by Mg2TaCuO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), and four equivalent O(2) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Ta(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Ta(1), and one Cu(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Ta(1) atoms to form distorted OMg2Ta2 trigonal pyramids that share corners with two equivalent O(4)Mg2Cu2 tetrahedra and corners with two equivalent O(3)Mg2Ta2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Mg(2), and two equivalent Cu(1) atoms to form OMg2Cu2 tetrahedra that share corners with two equivalent O(4)Mg2Cu2 tetrahedra and corners with two equivalent O(3)Mg2Ta2 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2TaCuO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.517
_cell_length_b   5.162
_cell_length_c   5.438
_cell_angle_alpha   86.513
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   210.586
_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
  Mg  Mg0  1  0.750  0.973  0.051  1.0
  Mg  Mg1  1  0.750  0.506  0.572  1.0
  Mg  Mg2  1  0.250  0.494  0.428  1.0
  Mg  Mg3  1  0.250  0.027  0.949  1.0
  Ta  Ta4  1  0.000  0.000  0.500  1.0
  Ta  Ta5  1  0.500  0.000  0.500  1.0
  Cu  Cu6  1  0.000  0.500  0.000  1.0
  Cu  Cu7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.435  0.182  0.182  1.0
  O  O9  1  0.571  0.694  0.325  1.0
  O  O10  1  0.565  0.818  0.818  1.0
  O  O11  1  0.071  0.306  0.675  1.0
  O  O12  1  0.250  0.864  0.551  1.0
  O  O13  1  0.429  0.306  0.675  1.0
  O  O14  1  0.929  0.694  0.325  1.0
  O  O15  1  0.065  0.182  0.182  1.0
  O  O16  1  0.750  0.367  0.936  1.0
  O  O17  1  0.935  0.818  0.818  1.0
  O  O18  1  0.250  0.633  0.064  1.0
  O  O19  1  0.750  0.136  0.449  1.0
[/CIF]
.
The material structure described by Mg2TaCuO6 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(4), and four equivalent O(2) atoms. Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with four equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with two equivalent Cu(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-45°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Ta(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Ta(1), and one Cu(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), and two equivalent Ta(1) atoms to form distorted OMg2Ta2 trigonal pyramids that share corners with two equivalent O(4)Mg2Cu2 tetrahedra and corners with two equivalent O(3)Mg2Ta2 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Mg(2), and two equivalent Cu(1) atoms to form OMg2Cu2 tetrahedra that share corners with two equivalent O(4)Mg2Cu2 tetrahedra and corners with two equivalent O(3)Mg2Ta2 trigonal pyramids. is represented by the CIF card [CIF]
data_Mg2TaCuO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.517
_cell_length_b   5.162
_cell_length_c   5.438
_cell_angle_alpha   86.513
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   210.586
_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
  Mg  Mg0  1  0.750  0.973  0.051  1.0
  Mg  Mg1  1  0.750  0.506  0.572  1.0
  Mg  Mg2  1  0.250  0.494  0.428  1.0
  Mg  Mg3  1  0.250  0.027  0.949  1.0
  Ta  Ta4  1  0.000  0.000  0.500  1.0
  Ta  Ta5  1  0.500  0.000  0.500  1.0
  Cu  Cu6  1  0.000  0.500  0.000  1.0
  Cu  Cu7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.435  0.182  0.182  1.0
  O  O9  1  0.571  0.694  0.325  1.0
  O  O10  1  0.565  0.818  0.818  1.0
  O  O11  1  0.071  0.306  0.675  1.0
  O  O12  1  0.250  0.864  0.551  1.0
  O  O13  1  0.429  0.306  0.675  1.0
  O  O14  1  0.929  0.694  0.325  1.0
  O  O15  1  0.065  0.182  0.182  1.0
  O  O16  1  0.750  0.367  0.936  1.0
  O  O17  1  0.935  0.818  0.818  1.0
  O  O18  1  0.250  0.633  0.064  1.0
  O  O19  1  0.750  0.136  0.449  1.0
[/CIF]
.