data_YMg2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.05
_cell_length_b   10.05
_cell_length_c   10.05
_cell_angle_alpha   20.08
_cell_angle_beta   20.08
_cell_angle_gamma   20.08
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YMg2Hg
_chemical_formula_sum   'Y1 Mg2 Hg1'
_cell_volume   104.61
_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  Y3  1  0.0  0.0  0.0  1.0
  Mg  Mg1  1  0.0  0.0  0.41  1.0
  Mg  Mg2  1  0.0  0.0  0.11  1.0
  Hg  Hg0  1  0.0  0.0  0.76  1.0

data_YMg2Hg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.07
_cell_length_b   3.5
_cell_length_c   10.05
_cell_angle_alpha   90.0
_cell_angle_beta   101.61
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   YMg2Hg
_chemical_formula_sum   'Y2 Mg4 Hg2'
_cell_volume   209.23
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.0  1.0
  Mg  Mg1  2  0.0  0.0  0.59  1.0
  Mg  Mg2  2  0.0  0.0  0.89  1.0
  Hg  Hg3  2  0.0  0.0  0.24  1.0

Y Mg Mg Hg
Mg2YHg crystallizes in the monoclinic Cm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one Mg(2), six equivalent Mg(1), and one Hg(1) atom. The Mg(1)-Mg(2) bond length is 3.00 Å. All Mg(1)-Mg(1) bond lengths are 3.50 Å. The Mg(1)-Hg(1) bond length is 3.52 Å. In the second Mg site, Mg(2) is bonded in a single-bond geometry to one Mg(1) and one Y(1) atom. The Mg(2)-Y(1) bond length is 1.13 Å. Y(1) is bonded in a linear geometry to one Mg(2) and one Hg(1) atom. The Y(1)-Hg(1) bond length is 2.39 Å. Hg(1) is bonded in a single-bond geometry to one Mg(1) and one Y(1) atom.