The crystal structure described by Mg2Ta2NiO8 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Ta(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are four inequivalent O sites. In the first O site, O(4) is bonded to three equivalent Mg(1) and one Ta(1) atom to form a mixture of corner and edge-sharing OMg3Ta trigonal pyramids. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Ni(1) atom. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ni(1) atoms. In the fourth O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Mg(1) and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Ta2NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.196
_cell_length_b   5.981
_cell_length_c   9.961
_cell_angle_alpha   107.475
_cell_angle_beta   90.198
_cell_angle_gamma   89.996
_symmetry_Int_Tables_number   1
_cell_volume   295.257
_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  0.245  0.871  0.456  1.0
  Mg  Mg1  1  0.255  0.417  0.546  1.0
  Mg  Mg2  1  0.754  0.130  0.546  1.0
  Mg  Mg3  1  0.745  0.584  0.455  1.0
  Ni  Ni4  1  0.250  0.643  0.001  1.0
  Ni  Ni5  1  0.750  0.359  0.001  1.0
  O  O6  1  0.919  0.044  0.860  1.0
  O  O7  1  0.580  0.184  0.141  1.0
  O  O8  1  0.080  0.957  0.141  1.0
  O  O9  1  0.419  0.817  0.861  1.0
  O  O10  1  0.414  0.319  0.885  1.0
  O  O11  1  0.086  0.434  0.117  1.0
  O  O12  1  0.586  0.683  0.117  1.0
  O  O13  1  0.914  0.567  0.885  1.0
  O  O14  1  0.544  0.918  0.630  1.0
  O  O15  1  0.955  0.289  0.372  1.0
  O  O16  1  0.044  0.712  0.629  1.0
  O  O17  1  0.455  0.083  0.372  1.0
  O  O18  1  0.620  0.456  0.619  1.0
  O  O19  1  0.880  0.837  0.383  1.0
  O  O20  1  0.380  0.546  0.382  1.0
  O  O21  1  0.120  0.164  0.619  1.0
  Ta  Ta22  1  0.257  0.050  0.771  1.0
  Ta  Ta23  1  0.243  0.280  0.231  1.0
  Ta  Ta24  1  0.743  0.951  0.231  1.0
  Ta  Ta25  1  0.757  0.722  0.771  1.0
[/CIF]
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The crystal structure described by Mg2Ta2NiO8 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Ta(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are four inequivalent O sites. In the first O site, O(4) is bonded to three equivalent Mg(1) and one Ta(1) atom to form a mixture of corner and edge-sharing OMg3Ta trigonal pyramids. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Ni(1) atom. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ni(1) atoms. In the fourth O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Mg(1) and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Ta2NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.196
_cell_length_b   5.981
_cell_length_c   9.961
_cell_angle_alpha   107.475
_cell_angle_beta   90.198
_cell_angle_gamma   89.996
_symmetry_Int_Tables_number   1
_cell_volume   295.257
_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  0.245  0.871  0.456  1.0
  Mg  Mg1  1  0.255  0.417  0.546  1.0
  Mg  Mg2  1  0.754  0.130  0.546  1.0
  Mg  Mg3  1  0.745  0.584  0.455  1.0
  Ni  Ni4  1  0.250  0.643  0.001  1.0
  Ni  Ni5  1  0.750  0.359  0.001  1.0
  O  O6  1  0.919  0.044  0.860  1.0
  O  O7  1  0.580  0.184  0.141  1.0
  O  O8  1  0.080  0.957  0.141  1.0
  O  O9  1  0.419  0.817  0.861  1.0
  O  O10  1  0.414  0.319  0.885  1.0
  O  O11  1  0.086  0.434  0.117  1.0
  O  O12  1  0.586  0.683  0.117  1.0
  O  O13  1  0.914  0.567  0.885  1.0
  O  O14  1  0.544  0.918  0.630  1.0
  O  O15  1  0.955  0.289  0.372  1.0
  O  O16  1  0.044  0.712  0.629  1.0
  O  O17  1  0.455  0.083  0.372  1.0
  O  O18  1  0.620  0.456  0.619  1.0
  O  O19  1  0.880  0.837  0.383  1.0
  O  O20  1  0.380  0.546  0.382  1.0
  O  O21  1  0.120  0.164  0.619  1.0
  Ta  Ta22  1  0.257  0.050  0.771  1.0
  Ta  Ta23  1  0.243  0.280  0.231  1.0
  Ta  Ta24  1  0.743  0.951  0.231  1.0
  Ta  Ta25  1  0.757  0.722  0.771  1.0
[/CIF]
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