The material described by KMgNi2H3(SeO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 6-coordinate geometry to one Se(2), one O(1), one O(10), one O(3), one O(4), and one O(9) atom. Mg(1) is bonded to one O(1); one O(10); one O(7); and two equivalent O(5,6) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Se(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10); one O(4); one O(5,6); one O(7); one O(8); and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second Ni site, Ni(2) is bonded to one O(10); one O(3); one O(5,6); one O(7); one O(8); and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(2) and one O(8) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(3), one O(4), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 52°. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one K(1); one O(2); and two equivalent O(5,6) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one K(1), one Mg(1), and one Se(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one H(2) and one Se(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Ni(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), and one Se(1) atom. In the fifth O site, O(5,6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(2), and one Se(2) atom. In the sixth O site, O(7) is bonded in a distorted single-bond geometry to one Mg(1), one Ni(1), one Ni(2), and one H(1) atom. In the seventh O site, O(8) is bonded in a water-like geometry to one Ni(1), one Ni(2), one H(2), and one H(3) atom. In the eighth O site, O(9) is bonded to one K(1), one Ni(1), one Ni(2), and one Se(1) atom to form distorted corner-sharing OKNi2Se tetrahedra. In the ninth O site, O(10) is bonded to one K(1), one Mg(1), one Ni(1), and one Ni(2) atom to form corner-sharing OKMgNi2 trigonal pyramids. is represented by the CIF file [CIF]
data_KMgNi2H3(SeO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.953
_cell_length_b   5.953
_cell_length_c   8.575
_cell_angle_alpha   62.086
_cell_angle_beta   62.061
_cell_angle_gamma   65.905
_symmetry_Int_Tables_number   1
_cell_volume   230.201
_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
  K  K0  1  0.483  0.484  0.454  1.0
  Mg  Mg1  1  0.565  0.566  0.767  1.0
  Ni  Ni2  1  0.017  0.510  0.977  1.0
  Ni  Ni3  1  0.509  0.017  0.977  1.0
  H  H4  1  0.824  0.824  0.732  1.0
  H  H5  1  0.184  0.183  0.307  1.0
  H  H6  1  0.377  0.374  0.168  1.0
  Se  Se7  1  0.890  0.890  0.248  1.0
  Se  Se8  1  0.114  0.114  0.666  1.0
  O  O9  1  0.750  0.750  0.480  1.0
  O  O10  1  0.039  0.039  0.528  1.0
  O  O11  1  0.217  0.790  0.191  1.0
  O  O12  1  0.790  0.217  0.191  1.0
  O  O13  1  0.812  0.216  0.818  1.0
  O  O14  1  0.216  0.812  0.817  1.0
  O  O15  1  0.721  0.721  0.859  1.0
  O  O16  1  0.278  0.277  0.168  1.0
  O  O17  1  0.779  0.779  0.154  1.0
  O  O18  1  0.331  0.331  0.820  1.0
[/CIF]
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The material described by KMgNi2H3(SeO5)2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 6-coordinate geometry to one Se(2), one O(1), one O(10), one O(3), one O(4), and one O(9) atom. Mg(1) is bonded to one O(1); one O(10); one O(7); and two equivalent O(5,6) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Se(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10); one O(4); one O(5,6); one O(7); one O(8); and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second Ni site, Ni(2) is bonded to one O(10); one O(3); one O(5,6); one O(7); one O(8); and one O(9) atom to form distorted NiO6 octahedra that share corners with two equivalent Se(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(2) and one O(8) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(3), one O(4), and one O(9) atom to form SeO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 52°. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one K(1); one O(2); and two equivalent O(5,6) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one K(1), one Mg(1), and one Se(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one H(2) and one Se(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Ni(2), and one Se(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Ni(1), and one Se(1) atom. In the fifth O site, O(5,6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(2), and one Se(2) atom. In the sixth O site, O(7) is bonded in a distorted single-bond geometry to one Mg(1), one Ni(1), one Ni(2), and one H(1) atom. In the seventh O site, O(8) is bonded in a water-like geometry to one Ni(1), one Ni(2), one H(2), and one H(3) atom. In the eighth O site, O(9) is bonded to one K(1), one Ni(1), one Ni(2), and one Se(1) atom to form distorted corner-sharing OKNi2Se tetrahedra. In the ninth O site, O(10) is bonded to one K(1), one Mg(1), one Ni(1), and one Ni(2) atom to form corner-sharing OKMgNi2 trigonal pyramids. is represented by the CIF file [CIF]
data_KMgNi2H3(SeO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.953
_cell_length_b   5.953
_cell_length_c   8.575
_cell_angle_alpha   62.086
_cell_angle_beta   62.061
_cell_angle_gamma   65.905
_symmetry_Int_Tables_number   1
_cell_volume   230.201
_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
  K  K0  1  0.483  0.484  0.454  1.0
  Mg  Mg1  1  0.565  0.566  0.767  1.0
  Ni  Ni2  1  0.017  0.510  0.977  1.0
  Ni  Ni3  1  0.509  0.017  0.977  1.0
  H  H4  1  0.824  0.824  0.732  1.0
  H  H5  1  0.184  0.183  0.307  1.0
  H  H6  1  0.377  0.374  0.168  1.0
  Se  Se7  1  0.890  0.890  0.248  1.0
  Se  Se8  1  0.114  0.114  0.666  1.0
  O  O9  1  0.750  0.750  0.480  1.0
  O  O10  1  0.039  0.039  0.528  1.0
  O  O11  1  0.217  0.790  0.191  1.0
  O  O12  1  0.790  0.217  0.191  1.0
  O  O13  1  0.812  0.216  0.818  1.0
  O  O14  1  0.216  0.812  0.817  1.0
  O  O15  1  0.721  0.721  0.859  1.0
  O  O16  1  0.278  0.277  0.168  1.0
  O  O17  1  0.779  0.779  0.154  1.0
  O  O18  1  0.331  0.331  0.820  1.0
[/CIF]
.