The material structure described by Ho2HgO4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1), two equivalent O(4), and three equivalent O(2) atoms to form distorted edge-sharing HoO7 pentagonal bipyramids. In the second Ho site, Ho(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), two equivalent O(1), and three equivalent O(3) atoms. Hg(1) is bonded in a linear geometry to one O(3) and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Ho(2) atoms to form OHo4 tetrahedra that share corners with two equivalent O(4)Ho3Hg tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(3)Ho3Hg tetrahedra,  an edgeedge with one O(3)Ho3Hg tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(4)Ho3Hg tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ho(2) and three equivalent Ho(1) atoms. In the third O site, O(3) is bonded to three equivalent Ho(2) and one Hg(1) atom to form distorted OHo3Hg tetrahedra that share corners with two equivalent O(3)Ho3Hg tetrahedra, corners with four equivalent O(4)Ho3Hg tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(3)Ho3Hg tetrahedra. In the fourth O site, O(4) is bonded to one Ho(2), two equivalent Ho(1), and one Hg(1) atom to form OHo3Hg tetrahedra that share corners with two equivalent O(4)Ho3Hg tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(3)Ho3Hg tetrahedra, and edges with two equivalent O(1)Ho4 tetrahedra. is represented by the CIF card [CIF]
data_Ho2HgO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.575
_cell_length_b   7.001
_cell_length_c   8.719
_cell_angle_alpha   78.622
_cell_angle_beta   78.171
_cell_angle_gamma   75.210
_symmetry_Int_Tables_number   1
_cell_volume   204.064
_cell_formula_units_Z   2
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
  Ho  Ho0  1  0.119  0.225  0.538  1.0
  Ho  Ho1  1  0.881  0.775  0.462  1.0
  Ho  Ho2  1  0.340  0.518  0.801  1.0
  Ho  Ho3  1  0.660  0.482  0.199  1.0
  Hg  Hg4  1  0.387  0.065  0.162  1.0
  Hg  Hg5  1  0.613  0.935  0.838  1.0
  O  O6  1  0.917  0.513  0.652  1.0
  O  O7  1  0.083  0.487  0.348  1.0
  O  O8  1  0.734  0.146  0.387  1.0
  O  O9  1  0.266  0.854  0.613  1.0
  O  O10  1  0.298  0.351  0.053  1.0
  O  O11  1  0.702  0.649  0.947  1.0
  O  O12  1  0.466  0.786  0.283  1.0
  O  O13  1  0.534  0.214  0.717  1.0
[/CIF]
.
The material structure described by Ho2HgO4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1), two equivalent O(4), and three equivalent O(2) atoms to form distorted edge-sharing HoO7 pentagonal bipyramids. In the second Ho site, Ho(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), two equivalent O(1), and three equivalent O(3) atoms. Hg(1) is bonded in a linear geometry to one O(3) and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Ho(2) atoms to form OHo4 tetrahedra that share corners with two equivalent O(4)Ho3Hg tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(3)Ho3Hg tetrahedra,  an edgeedge with one O(3)Ho3Hg tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(4)Ho3Hg tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ho(2) and three equivalent Ho(1) atoms. In the third O site, O(3) is bonded to three equivalent Ho(2) and one Hg(1) atom to form distorted OHo3Hg tetrahedra that share corners with two equivalent O(3)Ho3Hg tetrahedra, corners with four equivalent O(4)Ho3Hg tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(3)Ho3Hg tetrahedra. In the fourth O site, O(4) is bonded to one Ho(2), two equivalent Ho(1), and one Hg(1) atom to form OHo3Hg tetrahedra that share corners with two equivalent O(4)Ho3Hg tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(3)Ho3Hg tetrahedra, and edges with two equivalent O(1)Ho4 tetrahedra. is represented by the CIF card [CIF]
data_Ho2HgO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.575
_cell_length_b   7.001
_cell_length_c   8.719
_cell_angle_alpha   78.622
_cell_angle_beta   78.171
_cell_angle_gamma   75.210
_symmetry_Int_Tables_number   1
_cell_volume   204.064
_cell_formula_units_Z   2
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
  Ho  Ho0  1  0.119  0.225  0.538  1.0
  Ho  Ho1  1  0.881  0.775  0.462  1.0
  Ho  Ho2  1  0.340  0.518  0.801  1.0
  Ho  Ho3  1  0.660  0.482  0.199  1.0
  Hg  Hg4  1  0.387  0.065  0.162  1.0
  Hg  Hg5  1  0.613  0.935  0.838  1.0
  O  O6  1  0.917  0.513  0.652  1.0
  O  O7  1  0.083  0.487  0.348  1.0
  O  O8  1  0.734  0.146  0.387  1.0
  O  O9  1  0.266  0.854  0.613  1.0
  O  O10  1  0.298  0.351  0.053  1.0
  O  O11  1  0.702  0.649  0.947  1.0
  O  O12  1  0.466  0.786  0.283  1.0
  O  O13  1  0.534  0.214  0.717  1.0
[/CIF]
.