The structure described by MgHo2V2O7 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Ho(1)O6 octahedra, and edges with two equivalent V(1)O5 trigonal bipyramids. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted HoO6 octahedra that share corners with four equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. V(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form VO5 trigonal bipyramids that share corners with two equivalent Ho(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Ho(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one V(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 31-56°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ho(1), one Ho(2), and one V(1) atom to form distorted OHo2MgV trigonal pyramids that share corners with three equivalent O(1)Ho2MgV trigonal pyramids, corners with four equivalent O(3)Ho2V2 trigonal pyramids, and  an edgeedge with one O(3)Ho2V2 trigonal pyramid. In the second O site, O(2) is bonded in a distorted square co-planar geometry to one Mg(1), one Ho(1), one Ho(2), and one V(1) atom. In the third O site, O(3) is bonded to one Ho(1), one Ho(2), and two equivalent V(1) atoms to form OHo2V2 trigonal pyramids that share corners with four equivalent O(1)Ho2MgV trigonal pyramids,  an edgeedge with one O(1)Ho2MgV trigonal pyramid, and edges with two equivalent O(3)Ho2V2 trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1) and two equivalent V(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ho2MgV2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.910
_cell_length_b   5.910
_cell_length_c   5.461
_cell_angle_alpha   83.007
_cell_angle_beta   96.993
_cell_angle_gamma   66.050
_symmetry_Int_Tables_number   1
_cell_volume   169.915
_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
  Ho  Ho0  1  0.331  0.331  0.500  1.0
  Ho  Ho1  1  0.684  0.684  0.500  1.0
  Mg  Mg2  1  0.212  0.212  0.000  1.0
  V  V3  1  0.259  0.740  0.885  1.0
  V  V4  1  0.740  0.259  0.115  1.0
  O  O5  1  0.070  0.550  0.746  1.0
  O  O6  1  0.397  0.966  0.727  1.0
  O  O7  1  0.450  0.565  0.229  1.0
  O  O8  1  0.565  0.450  0.771  1.0
  O  O9  1  0.015  0.015  0.000  1.0
  O  O10  1  0.550  0.070  0.254  1.0
  O  O11  1  0.966  0.397  0.273  1.0
[/CIF]
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The structure described by MgHo2V2O7 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO5 trigonal bipyramids that share corners with two equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Ho(1)O6 octahedra, and edges with two equivalent V(1)O5 trigonal bipyramids. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted HoO6 octahedra that share corners with four equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. V(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form VO5 trigonal bipyramids that share corners with two equivalent Ho(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one V(1)O5 trigonal bipyramid,  an edgeedge with one Ho(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one V(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 31-56°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ho(1), one Ho(2), and one V(1) atom to form distorted OHo2MgV trigonal pyramids that share corners with three equivalent O(1)Ho2MgV trigonal pyramids, corners with four equivalent O(3)Ho2V2 trigonal pyramids, and  an edgeedge with one O(3)Ho2V2 trigonal pyramid. In the second O site, O(2) is bonded in a distorted square co-planar geometry to one Mg(1), one Ho(1), one Ho(2), and one V(1) atom. In the third O site, O(3) is bonded to one Ho(1), one Ho(2), and two equivalent V(1) atoms to form OHo2V2 trigonal pyramids that share corners with four equivalent O(1)Ho2MgV trigonal pyramids,  an edgeedge with one O(1)Ho2MgV trigonal pyramid, and edges with two equivalent O(3)Ho2V2 trigonal pyramids. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1) and two equivalent V(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ho2MgV2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.910
_cell_length_b   5.910
_cell_length_c   5.461
_cell_angle_alpha   83.007
_cell_angle_beta   96.993
_cell_angle_gamma   66.050
_symmetry_Int_Tables_number   1
_cell_volume   169.915
_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
  Ho  Ho0  1  0.331  0.331  0.500  1.0
  Ho  Ho1  1  0.684  0.684  0.500  1.0
  Mg  Mg2  1  0.212  0.212  0.000  1.0
  V  V3  1  0.259  0.740  0.885  1.0
  V  V4  1  0.740  0.259  0.115  1.0
  O  O5  1  0.070  0.550  0.746  1.0
  O  O6  1  0.397  0.966  0.727  1.0
  O  O7  1  0.450  0.565  0.229  1.0
  O  O8  1  0.565  0.450  0.771  1.0
  O  O9  1  0.015  0.015  0.000  1.0
  O  O10  1  0.550  0.070  0.254  1.0
  O  O11  1  0.966  0.397  0.273  1.0
[/CIF]
.