The material described by MgTa4(CuO6)2 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, edges with two equivalent Ta(2)O6 octahedra, edges with two equivalent Ta(3)O6 octahedra, and faces with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ta(3)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra,  an edgeedge with one Ta(4)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-51°. In the second Ta site, Ta(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(4)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-52°. In the third Ta site, Ta(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-54°. In the fourth Ta site, Ta(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-52°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(4)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the second Cu site, Cu(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted CuO6 octahedra that share corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Ta(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(4)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(3), and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(2), one Ta(4), and one Cu(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ta(2), one Ta(4), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ta(1), one Ta(3), and one Cu(2) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Ta(2), one Ta(3), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing OMgTa2Cu trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(4), and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTa4(CuO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.087
_cell_length_b   4.931
_cell_length_c   8.921
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.103
_symmetry_Int_Tables_number   1
_cell_volume   223.778
_cell_formula_units_Z   1
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  0.000  0.500  0.006  1.0
  Ta  Ta1  1  0.000  0.000  0.675  1.0
  Ta  Ta2  1  0.500  0.500  0.189  1.0
  Ta  Ta3  1  0.500  0.500  0.819  1.0
  Ta  Ta4  1  0.000  0.000  0.333  1.0
  Cu  Cu5  1  0.500  0.500  0.505  1.0
  Cu  Cu6  1  0.000  0.000  0.999  1.0
  O  O7  1  0.693  0.744  0.688  1.0
  O  O8  1  0.307  0.256  0.688  1.0
  O  O9  1  0.694  0.744  0.319  1.0
  O  O10  1  0.181  0.749  0.179  1.0
  O  O11  1  0.819  0.251  0.179  1.0
  O  O12  1  0.819  0.252  0.828  1.0
  O  O13  1  0.337  0.311  0.004  1.0
  O  O14  1  0.163  0.804  0.504  1.0
  O  O15  1  0.837  0.196  0.504  1.0
  O  O16  1  0.663  0.689  0.004  1.0
  O  O17  1  0.306  0.256  0.319  1.0
  O  O18  1  0.181  0.748  0.828  1.0
[/CIF]
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The material described by MgTa4(CuO6)2 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, edges with two equivalent Ta(2)O6 octahedra, edges with two equivalent Ta(3)O6 octahedra, and faces with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ta(3)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra,  an edgeedge with one Ta(4)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-51°. In the second Ta site, Ta(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(4)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-52°. In the third Ta site, Ta(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form TaO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Cu(2)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-54°. In the fourth Ta site, Ta(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Cu(1)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-52°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form CuO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(4)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the second Cu site, Cu(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted CuO6 octahedra that share corners with four equivalent Ta(2)O6 octahedra, corners with four equivalent Ta(3)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra,  an edgeedge with one Ta(4)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(3), and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(2), one Ta(4), and one Cu(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ta(2), one Ta(4), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ta(1), one Ta(3), and one Cu(2) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Ta(2), one Ta(3), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing OMgTa2Cu trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(4), and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgTa4(CuO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.087
_cell_length_b   4.931
_cell_length_c   8.921
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.103
_symmetry_Int_Tables_number   1
_cell_volume   223.778
_cell_formula_units_Z   1
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  0.000  0.500  0.006  1.0
  Ta  Ta1  1  0.000  0.000  0.675  1.0
  Ta  Ta2  1  0.500  0.500  0.189  1.0
  Ta  Ta3  1  0.500  0.500  0.819  1.0
  Ta  Ta4  1  0.000  0.000  0.333  1.0
  Cu  Cu5  1  0.500  0.500  0.505  1.0
  Cu  Cu6  1  0.000  0.000  0.999  1.0
  O  O7  1  0.693  0.744  0.688  1.0
  O  O8  1  0.307  0.256  0.688  1.0
  O  O9  1  0.694  0.744  0.319  1.0
  O  O10  1  0.181  0.749  0.179  1.0
  O  O11  1  0.819  0.251  0.179  1.0
  O  O12  1  0.819  0.252  0.828  1.0
  O  O13  1  0.337  0.311  0.004  1.0
  O  O14  1  0.163  0.804  0.504  1.0
  O  O15  1  0.837  0.196  0.504  1.0
  O  O16  1  0.663  0.689  0.004  1.0
  O  O17  1  0.306  0.256  0.319  1.0
  O  O18  1  0.181  0.748  0.828  1.0
[/CIF]
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