data_HfMg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.01
_cell_length_b   7.01
_cell_length_c   7.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfMg2
_chemical_formula_sum   'Hf4 Mg8'
_cell_volume   345.06
_cell_formula_units_Z   4
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
  Hf  Hf0  1  0.0  0.0  0.0  1.0
  Hf  Hf1  1  0.0  0.51  0.51  1.0
  Hf  Hf2  1  0.51  0.0  0.51  1.0
  Hf  Hf3  1  0.51  0.51  0.0  1.0
  Mg  Mg4  1  0.87  0.37  0.15  1.0
  Mg  Mg5  1  0.87  0.15  0.64  1.0
  Mg  Mg6  1  0.64  0.87  0.15  1.0
  Mg  Mg7  1  0.64  0.64  0.64  1.0
  Mg  Mg8  1  0.37  0.37  0.37  1.0
  Mg  Mg9  1  0.37  0.15  0.87  1.0
  Mg  Mg10  1  0.15  0.87  0.37  1.0
  Mg  Mg11  1  0.15  0.64  0.87  1.0

data_HfMg2
_symmetry_space_group_name_H-M   R3
_cell_length_a   9.92
_cell_length_b   9.92
_cell_length_c   12.15
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   HfMg2
_chemical_formula_sum   'Hf12 Mg24'
_cell_volume   1035.17
_cell_formula_units_Z   12
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  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+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
  Hf  Hf0  9  0.17  0.34  0.34  1.0
  Hf  Hf1  3  0.0  0.0  0.0  1.0
  Mg  Mg2  9  0.02  0.76  0.13  1.0
  Mg  Mg3  9  0.09  0.4  0.55  1.0
  Mg  Mg4  3  0.0  0.0  0.37  1.0
  Mg  Mg5  3  0.0  0.0  0.64  1.0

Hf Hf Hf Hf Mg Mg Mg Mg Mg Mg Mg Mg
Mg2Hf is Ilmenite-derived structured and crystallizes in the trigonal R3 space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Mg(2); one Hf(1); and two Hf(2,2) atoms to form distorted MgHf3Mg trigonal pyramids that share  a cornercorner with one Hf(1)Mg6 octahedra; corners with two equivalent Hf(2)Mg6 octahedra; corners with two equivalent Mg(3)Hf3Mg trigonal pyramids; corners with two equivalent Mg(4)Hf3Mg trigonal pyramids; corners with four equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with seven Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 82-85°. The Mg(1)-Mg(2) bond length is 3.38 Å. The Mg(1)-Hf(1) bond length is 2.97 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Mg(1)-Hf(2,2) bond length. In the second Mg site, Mg(2) is bonded to one Mg(1); one Hf(1); and two Hf(2,2) atoms to form distorted MgHf3Mg trigonal pyramids that share  a cornercorner with one Hf(1)Mg6 octahedra; corners with two Hf(2,2)Mg6 octahedra; corners with two equivalent Mg(3)Hf3Mg trigonal pyramids; corners with two equivalent Mg(4)Hf3Mg trigonal pyramids; corners with four Mg(2,2)Hf3Mg trigonal pyramids; and corners with seven equivalent Mg(1)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 82-84°. The Mg(2)-Hf(1) bond length is 2.88 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Mg(2)-Hf(2,2) bond length. In the third Mg site, Mg(3) is bonded to one Mg(4) and three Hf(2,2,2) atoms to form MgHf3Mg trigonal pyramids that share corners with three equivalent Hf(2)Mg6 octahedra; corners with three equivalent Mg(4)Hf3Mg trigonal pyramids; corners with six equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with six Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles are 82°. The Mg(3)-Mg(4) bond length is 3.27 Å. All Mg(3)-Hf(2,2,2) bond lengths are 2.85 Å. In the fourth Mg site, Mg(4) is bonded to one Mg(3) and three equivalent Hf(2) atoms to form MgHf3Mg trigonal pyramids that share corners with three Hf(2,2,2)Mg6 octahedra; corners with three equivalent Mg(3)Hf3Mg trigonal pyramids; corners with six equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with six Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles are 83°. All Mg(4)-Hf(2) bond lengths are 2.93 Å. In the fifth Mg site, Mg(2) is bonded to one Mg(1); one Hf(1); and two Hf(2,2) atoms to form distorted MgHf3Mg trigonal pyramids that share  a cornercorner with one Hf(1)Mg6 octahedra; corners with two Hf(2,2)Mg6 octahedra; corners with two equivalent Mg(3)Hf3Mg trigonal pyramids; corners with two equivalent Mg(4)Hf3Mg trigonal pyramids; corners with four Mg(2,2)Hf3Mg trigonal pyramids; and corners with seven equivalent Mg(1)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 82-84°. The Mg(2)-Mg(1) bond length is 3.38 Å. The Mg(2)-Hf(1) bond length is 2.88 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Mg(2)-Hf(2,2) bond length. There are seven inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to three equivalent Mg(1) and three equivalent Mg(2) atoms to form HfMg6 octahedra that share corners with twelve Hf(2,2,2,2,2,2)Mg6 octahedra; corners with three equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with three Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. In the second Hf site, Hf(2) is bonded to one Mg(3); one Mg(4); two equivalent Mg(1); and two Mg(2,2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two equivalent Mg(2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(2) bond length is 2.85 Å. In the third Hf site, Hf(2) is bonded to one Mg(3); one Mg(4); two equivalent Mg(1); and two Mg(2,2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(4) bond length is 2.93 Å. The Hf(2)-Mg(2) bond length is 2.88 Å. In the fourth Hf site, Hf(2) is bonded to one Mg(3); one Mg(4); two equivalent Mg(1); and two Mg(2,2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(4) bond length is 2.93 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(1) bond length. The Hf(2)-Mg(2) bond length is 2.85 Å. In the fifth Hf site, Hf(2) is bonded to one Mg(3); one Mg(4); two equivalent Mg(1); and two Mg(2,2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two equivalent Mg(2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(3) bond length is 2.85 Å. The Hf(2)-Mg(4) bond length is 2.93 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(1) bond length. The Hf(2)-Mg(2) bond length is 2.88 Å. In the sixth Hf site, Hf(2) is bonded to one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(3) bond length is 2.85 Å. The Hf(2)-Mg(4) bond length is 2.93 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(1) bond length. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(2) bond length. In the seventh Hf site, Hf(2) is bonded to one Mg(3); one Mg(4); two equivalent Mg(1); and two Mg(2,2) atoms to form HfMg6 octahedra that share corners with four equivalent Hf(1)Mg6 octahedra; corners with eight Hf(2,2,2,2,2)Mg6 octahedra;  a cornercorner with one Mg(3)Hf3Mg trigonal pyramid;  a cornercorner with one Mg(4)Hf3Mg trigonal pyramid; corners with two equivalent Mg(1)Hf3Mg trigonal pyramids; and corners with two Mg(2,2)Hf3Mg trigonal pyramids. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(2)-Mg(3) bond length is 2.85 Å. The Hf(2)-Mg(4) bond length is 2.93 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(1) bond length. There is one shorter (2.85 Å) and one longer (2.88 Å) Hf(2)-Mg(2,2) bond length.