data_Y2HfMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.41
_cell_length_b   3.41
_cell_length_c   9.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.88
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Y2HfMg
_chemical_formula_sum   'Y2 Hf1 Mg1'
_cell_volume   108.64
_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  0.4  0.0  0.39  1.0
  Y  Y3  1  0.4  0.0  0.94  1.0
  Hf  Hf0  1  0.0  0.0  0.66  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0

data_Y2HfMg
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.41
_cell_length_b   3.41
_cell_length_c   9.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   Y2HfMg
_chemical_formula_sum   'Y2 Hf1 Mg1'
_cell_volume   108.66
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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  Y0  1  0.4  0.0  0.39  1.0
  Y  Y1  1  0.4  0.0  0.94  1.0
  Hf  Hf2  1  0.0  0.0  0.66  1.0
  Mg  Mg3  1  0.0  0.0  0.0  1.0

Y Y Hf Mg
MgY2Hf crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a distorted bent 150 degrees geometry to one Y(1), two equivalent Y(2), and one Hf(1) atom. The Mg(1)-Y(1) bond length is 3.87 Å. There is one shorter (1.48 Å) and one longer (2.15 Å) Mg(1)-Y(2) bond length. The Mg(1)-Hf(1) bond length is 3.15 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one Mg(1), four equivalent Y(1), and two equivalent Hf(1) atoms to form a mixture of distorted corner and edge-sharing YY4Hf2Mg hexagonal pyramids. All Y(1)-Y(1) bond lengths are 3.41 Å. There is one shorter (2.88 Å) and one longer (3.28 Å) Y(1)-Hf(1) bond length. In the second Y site, Y(2) is bonded in a 2-coordinate geometry to two equivalent Mg(1) and two equivalent Hf(1) atoms. There is one shorter (2.88 Å) and one longer (3.28 Å) Y(2)-Hf(1) bond length. Hf(1) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Y(1), two equivalent Y(2), and four equivalent Hf(1) atoms. All Hf(1)-Hf(1) bond lengths are 3.41 Å.