The crystal structure described by MgTa3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Ta(1) and eight equivalent Ta(2) atoms to form MgTa12 cuboctahedra that share corners with four equivalent Mg(1)Ta12 cuboctahedra, corners with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eight equivalent Mg(1)Ta12 cuboctahedra, edges with sixteen equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, faces with six equivalent Ta(1)Mg4Ta8 cuboctahedra, and faces with eight equivalent Ta(2)Mg4Ta8 cuboctahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to four equivalent Mg(1) and eight equivalent Ta(2) atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent Ta(1)Mg4Ta8 cuboctahedra, corners with eight equivalent Mg(1)Ta12 cuboctahedra, edges with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with sixteen equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with six equivalent Mg(1)Ta12 cuboctahedra, and faces with eight equivalent Ta(2)Mg4Ta8 cuboctahedra. In the second Ta site, Ta(2) is bonded to four equivalent Mg(1), four equivalent Ta(1), and four equivalent Ta(2) atoms to form distorted TaMg4Ta8 cuboctahedra that share corners with twelve equivalent Ta(2)Mg4Ta8 cuboctahedra, edges with eight equivalent Mg(1)Ta12 cuboctahedra, edges with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eight equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, faces with four equivalent Ta(1)Mg4Ta8 cuboctahedra, and faces with ten equivalent Ta(2)Mg4Ta8 cuboctahedra. is represented by the CIF file [CIF]
data_MgTa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.059
_cell_length_b   5.059
_cell_length_c   5.059
_cell_angle_alpha   129.949
_cell_angle_beta   129.949
_cell_angle_gamma   73.488
_symmetry_Int_Tables_number   1
_cell_volume   74.245
_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  0.000  0.000  1.0
  Ta  Ta1  1  0.500  0.500  0.000  1.0
  Ta  Ta2  1  0.750  0.250  0.500  1.0
  Ta  Ta3  1  0.250  0.750  0.500  1.0
[/CIF]
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The crystal structure described by MgTa3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Ta(1) and eight equivalent Ta(2) atoms to form MgTa12 cuboctahedra that share corners with four equivalent Mg(1)Ta12 cuboctahedra, corners with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eight equivalent Mg(1)Ta12 cuboctahedra, edges with sixteen equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, faces with six equivalent Ta(1)Mg4Ta8 cuboctahedra, and faces with eight equivalent Ta(2)Mg4Ta8 cuboctahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to four equivalent Mg(1) and eight equivalent Ta(2) atoms to form TaMg4Ta8 cuboctahedra that share corners with four equivalent Ta(1)Mg4Ta8 cuboctahedra, corners with eight equivalent Mg(1)Ta12 cuboctahedra, edges with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with sixteen equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Ta(1)Mg4Ta8 cuboctahedra, faces with six equivalent Mg(1)Ta12 cuboctahedra, and faces with eight equivalent Ta(2)Mg4Ta8 cuboctahedra. In the second Ta site, Ta(2) is bonded to four equivalent Mg(1), four equivalent Ta(1), and four equivalent Ta(2) atoms to form distorted TaMg4Ta8 cuboctahedra that share corners with twelve equivalent Ta(2)Mg4Ta8 cuboctahedra, edges with eight equivalent Mg(1)Ta12 cuboctahedra, edges with eight equivalent Ta(1)Mg4Ta8 cuboctahedra, edges with eight equivalent Ta(2)Mg4Ta8 cuboctahedra, faces with four equivalent Mg(1)Ta12 cuboctahedra, faces with four equivalent Ta(1)Mg4Ta8 cuboctahedra, and faces with ten equivalent Ta(2)Mg4Ta8 cuboctahedra. is represented by the CIF file [CIF]
data_MgTa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.059
_cell_length_b   5.059
_cell_length_c   5.059
_cell_angle_alpha   129.949
_cell_angle_beta   129.949
_cell_angle_gamma   73.488
_symmetry_Int_Tables_number   1
_cell_volume   74.245
_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  0.000  0.000  1.0
  Ta  Ta1  1  0.500  0.500  0.000  1.0
  Ta  Ta2  1  0.750  0.250  0.500  1.0
  Ta  Ta3  1  0.250  0.750  0.500  1.0
[/CIF]
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