The crystal structure described by NaCu2H2(SeO5)2 crystallizes in the monoclinic C2/m space group. Na(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted NaO8 hexagonal bipyramids that share corners with four equivalent Se(1)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with two equivalent Se(1)O4 tetrahedra. Cu(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with four equivalent Se(1)O4 tetrahedra, edges with two equivalent Na(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. H(1) is bonded in a single-bond geometry to one O(4) atom. Se(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SeO4 tetrahedra that share corners with two equivalent Na(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one Na(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 43-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Cu(1), and one Se(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Na(1) and one Se(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one Cu(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu(1) and one H(1) atom. is represented by the CIF file [CIF]
data_NaCu2H2(SeO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.684
_cell_length_b   5.684
_cell_length_c   7.926
_cell_angle_alpha   64.765
_cell_angle_beta   64.765
_cell_angle_gamma   68.065
_symmetry_Int_Tables_number   1
_cell_volume   203.694
_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
  Na  Na0  1  0.500  0.500  0.500  1.0
  Cu  Cu1  1  0.000  0.500  0.000  1.0
  Cu  Cu2  1  0.500  0.000  0.000  1.0
  H  H3  1  0.711  0.711  0.796  1.0
  H  H4  1  0.289  0.289  0.204  1.0
  Se  Se5  1  0.084  0.084  0.701  1.0
  Se  Se6  1  0.916  0.916  0.299  1.0
  O  O7  1  0.183  0.183  0.826  1.0
  O  O8  1  0.817  0.817  0.174  1.0
  O  O9  1  0.227  0.227  0.464  1.0
  O  O10  1  0.773  0.773  0.536  1.0
  O  O11  1  0.744  0.185  0.752  1.0
  O  O12  1  0.185  0.744  0.752  1.0
  O  O13  1  0.256  0.815  0.248  1.0
  O  O14  1  0.815  0.256  0.248  1.0
  O  O15  1  0.676  0.676  0.938  1.0
  O  O16  1  0.324  0.324  0.062  1.0
[/CIF]
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The crystal structure described by NaCu2H2(SeO5)2 crystallizes in the monoclinic C2/m space group. Na(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted NaO8 hexagonal bipyramids that share corners with four equivalent Se(1)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra, and edges with two equivalent Se(1)O4 tetrahedra. Cu(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form CuO6 octahedra that share corners with four equivalent Se(1)O4 tetrahedra, edges with two equivalent Na(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. H(1) is bonded in a single-bond geometry to one O(4) atom. Se(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SeO4 tetrahedra that share corners with two equivalent Na(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one Na(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 43-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Cu(1), and one Se(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Na(1) and one Se(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one Cu(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cu(1) and one H(1) atom. is represented by the CIF file [CIF]
data_NaCu2H2(SeO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.684
_cell_length_b   5.684
_cell_length_c   7.926
_cell_angle_alpha   64.765
_cell_angle_beta   64.765
_cell_angle_gamma   68.065
_symmetry_Int_Tables_number   1
_cell_volume   203.694
_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
  Na  Na0  1  0.500  0.500  0.500  1.0
  Cu  Cu1  1  0.000  0.500  0.000  1.0
  Cu  Cu2  1  0.500  0.000  0.000  1.0
  H  H3  1  0.711  0.711  0.796  1.0
  H  H4  1  0.289  0.289  0.204  1.0
  Se  Se5  1  0.084  0.084  0.701  1.0
  Se  Se6  1  0.916  0.916  0.299  1.0
  O  O7  1  0.183  0.183  0.826  1.0
  O  O8  1  0.817  0.817  0.174  1.0
  O  O9  1  0.227  0.227  0.464  1.0
  O  O10  1  0.773  0.773  0.536  1.0
  O  O11  1  0.744  0.185  0.752  1.0
  O  O12  1  0.185  0.744  0.752  1.0
  O  O13  1  0.256  0.815  0.248  1.0
  O  O14  1  0.815  0.256  0.248  1.0
  O  O15  1  0.676  0.676  0.938  1.0
  O  O16  1  0.324  0.324  0.062  1.0
[/CIF]
.