data_Y2MgTa
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   5.17
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Y2MgTa
_chemical_formula_sum   'Y2 Mg1 Ta1'
_cell_volume   97.89
_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
  Y  Y2  1  0.66  0.66  0.66  1.0
  Y  Y3  1  0.49  0.49  0.49  1.0
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Ta  Ta1  1  0.83  0.83  0.83  1.0

data_Y2MgTa
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   12.67
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Y2MgTa
_chemical_formula_sum   'Y6 Mg3 Ta3'
_cell_volume   293.67
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Y  Y0  3  0.0  0.0  0.34  1.0
  Y  Y1  3  0.0  0.0  0.51  1.0
  Mg  Mg2  3  0.0  0.0  0.0  1.0
  Ta  Ta3  3  0.0  0.0  0.17  1.0

Y Y Mg Ta
MgY2Ta crystallizes in the trigonal R3m space group. Mg(1) is bonded in a distorted single-bond geometry to one Ta(1) atom. The Mg(1)-Ta(1) bond length is 2.17 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a distorted single-bond geometry to one Y(2) and one Ta(1) atom. The Y(1)-Y(2) bond length is 2.17 Å. The Y(1)-Ta(1) bond length is 2.17 Å. In the second Y site, Y(2) is bonded to one Y(1) and three equivalent Ta(1) atoms to form distorted YYTa3 trigonal pyramids that share  a cornercorner with one Ta(1)Y4Mg trigonal bipyramid and corners with six equivalent Y(2)YTa3 trigonal pyramids. All Y(2)-Ta(1) bond lengths are 2.99 Å. Ta(1) is bonded to one Mg(1), one Y(1), and three equivalent Y(2) atoms to form distorted TaY4Mg trigonal bipyramids that share corners with six equivalent Ta(1)Y4Mg trigonal bipyramids and  a cornercorner with one Y(2)YTa3 trigonal pyramid.