The structure described by KCu2H3(SO5)2 crystallizes in the monoclinic Cm space group. K(1) is bonded to one O(3), one O(4), one O(7), one O(8), two equivalent O(1), and two equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra,  an edgeedge with one S(1)O4 tetrahedra, and  an edgeedge with one S(2)O4 tetrahedra. Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form CuO6 octahedra that share corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) atom. In the third H site, H(3) is bonded in a linear geometry to one O(5) and one O(6) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(3), one O(7), and two equivalent O(1) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 43-48°. In the second S site, S(2) is bonded to one O(4), one O(8), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 45-49°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1) and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted water-like geometry to two equivalent Cu(1), one H(1), and one H(3) atom. In the sixth O site, O(6) is bonded in a distorted tetrahedral geometry to two equivalent Cu(1), one H(2), and one H(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_KCu2H3(SO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.563
_cell_length_b   5.563
_cell_length_c   7.820
_cell_angle_alpha   67.069
_cell_angle_beta   67.069
_cell_angle_gamma   70.203
_symmetry_Int_Tables_number   1
_cell_volume   200.230
_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  0.500  0.500  0.500  1.0
  Cu  Cu1  1  0.504  0.995  0.998  1.0
  Cu  Cu2  1  0.995  0.504  0.998  1.0
  H  H3  1  0.297  0.297  0.218  1.0
  H  H4  1  0.703  0.703  0.785  1.0
  H  H5  1  0.479  0.479  0.012  1.0
  S  S6  1  0.921  0.921  0.285  1.0
  S  S7  1  0.079  0.079  0.715  1.0
  O  O8  1  0.837  0.223  0.226  1.0
  O  O9  1  0.223  0.837  0.226  1.0
  O  O10  1  0.164  0.777  0.773  1.0
  O  O11  1  0.777  0.164  0.773  1.0
  O  O12  1  0.817  0.817  0.496  1.0
  O  O13  1  0.184  0.184  0.503  1.0
  O  O14  1  0.344  0.344  0.075  1.0
  O  O15  1  0.656  0.656  0.928  1.0
  O  O16  1  0.816  0.816  0.187  1.0
  O  O17  1  0.184  0.184  0.813  1.0
[/CIF]
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The structure described by KCu2H3(SO5)2 crystallizes in the monoclinic Cm space group. K(1) is bonded to one O(3), one O(4), one O(7), one O(8), two equivalent O(1), and two equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, edges with four equivalent Cu(1)O6 octahedra,  an edgeedge with one S(1)O4 tetrahedra, and  an edgeedge with one S(2)O4 tetrahedra. Cu(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form CuO6 octahedra that share corners with two equivalent S(1)O4 tetrahedra, corners with two equivalent S(2)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with two equivalent Cu(1)O6 octahedra. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(6) atom. In the third H site, H(3) is bonded in a linear geometry to one O(5) and one O(6) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(3), one O(7), and two equivalent O(1) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 43-48°. In the second S site, S(2) is bonded to one O(4), one O(8), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Cu(1)O6 octahedra, and  an edgeedge with one K(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 45-49°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one S(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(1) and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted water-like geometry to two equivalent Cu(1), one H(1), and one H(3) atom. In the sixth O site, O(6) is bonded in a distorted tetrahedral geometry to two equivalent Cu(1), one H(2), and one H(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one K(1), two equivalent Cu(1), and one S(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_KCu2H3(SO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.563
_cell_length_b   5.563
_cell_length_c   7.820
_cell_angle_alpha   67.069
_cell_angle_beta   67.069
_cell_angle_gamma   70.203
_symmetry_Int_Tables_number   1
_cell_volume   200.230
_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  0.500  0.500  0.500  1.0
  Cu  Cu1  1  0.504  0.995  0.998  1.0
  Cu  Cu2  1  0.995  0.504  0.998  1.0
  H  H3  1  0.297  0.297  0.218  1.0
  H  H4  1  0.703  0.703  0.785  1.0
  H  H5  1  0.479  0.479  0.012  1.0
  S  S6  1  0.921  0.921  0.285  1.0
  S  S7  1  0.079  0.079  0.715  1.0
  O  O8  1  0.837  0.223  0.226  1.0
  O  O9  1  0.223  0.837  0.226  1.0
  O  O10  1  0.164  0.777  0.773  1.0
  O  O11  1  0.777  0.164  0.773  1.0
  O  O12  1  0.817  0.817  0.496  1.0
  O  O13  1  0.184  0.184  0.503  1.0
  O  O14  1  0.344  0.344  0.075  1.0
  O  O15  1  0.656  0.656  0.928  1.0
  O  O16  1  0.816  0.816  0.187  1.0
  O  O17  1  0.184  0.184  0.813  1.0
[/CIF]
.