The crystal structure described by ErH(SO4)2 crystallizes in the monoclinic P2_1/c space group. Er(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form ErO7 pentagonal bipyramids that share corners with three equivalent S(1)O4 tetrahedra and corners with four equivalent S(2)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one O(6) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SO4 tetrahedra that share corners with three equivalent Er(1)O7 pentagonal bipyramids. In the second S site, S(2) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form SO4 tetrahedra that share corners with four equivalent Er(1)O7 pentagonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Er(1) and one S(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Er(1) and one S(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Er(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Er(1) and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Er(1) and one S(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one H(1) and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one S(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one S(2) atom. is represented by the CIF file [CIF]
data_ErH(SO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.869
_cell_length_b   5.508
_cell_length_c   10.662
_cell_angle_alpha   74.578
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   615.309
_cell_formula_units_Z   4
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
  Er  Er0  1  0.167  0.264  0.848  1.0
  Er  Er1  1  0.667  0.736  0.652  1.0
  Er  Er2  1  0.333  0.264  0.348  1.0
  Er  Er3  1  0.833  0.736  0.152  1.0
  H  H4  1  0.024  0.849  0.395  1.0
  H  H5  1  0.524  0.151  0.105  1.0
  H  H6  1  0.476  0.849  0.895  1.0
  H  H7  1  0.976  0.151  0.605  1.0
  S  S8  1  0.682  0.324  0.995  1.0
  S  S9  1  0.182  0.676  0.505  1.0
  S  S10  1  0.545  0.790  0.320  1.0
  S  S11  1  0.955  0.790  0.820  1.0
  S  S12  1  0.045  0.210  0.180  1.0
  S  S13  1  0.455  0.210  0.680  1.0
  S  S14  1  0.818  0.324  0.495  1.0
  S  S15  1  0.318  0.676  0.005  1.0
  O  O16  1  0.789  0.448  0.597  1.0
  O  O17  1  0.510  0.447  0.691  1.0
  O  O18  1  0.185  0.502  0.634  1.0
  O  O19  1  0.685  0.498  0.866  1.0
  O  O20  1  0.010  0.553  0.809  1.0
  O  O21  1  0.655  0.853  0.235  1.0
  O  O22  1  0.575  0.776  0.456  1.0
  O  O23  1  0.044  0.760  0.488  1.0
  O  O24  1  0.289  0.552  0.903  1.0
  O  O25  1  0.759  0.103  0.003  1.0
  O  O26  1  0.955  0.996  0.230  1.0
  O  O27  1  0.455  0.004  0.270  1.0
  O  O28  1  0.259  0.897  0.497  1.0
  O  O29  1  0.845  0.853  0.735  1.0
  O  O30  1  0.544  0.240  0.012  1.0
  O  O31  1  0.075  0.224  0.044  1.0
  O  O32  1  0.925  0.776  0.956  1.0
  O  O33  1  0.456  0.760  0.988  1.0
  O  O34  1  0.155  0.147  0.265  1.0
  O  O35  1  0.741  0.103  0.503  1.0
  O  O36  1  0.545  0.996  0.730  1.0
  O  O37  1  0.045  0.004  0.770  1.0
  O  O38  1  0.241  0.897  0.997  1.0
  O  O39  1  0.711  0.448  0.097  1.0
  O  O40  1  0.956  0.240  0.512  1.0
  O  O41  1  0.425  0.224  0.544  1.0
  O  O42  1  0.345  0.147  0.765  1.0
  O  O43  1  0.990  0.447  0.191  1.0
  O  O44  1  0.315  0.502  0.134  1.0
  O  O45  1  0.815  0.498  0.366  1.0
  O  O46  1  0.490  0.553  0.309  1.0
  O  O47  1  0.211  0.552  0.403  1.0
[/CIF]
.
The crystal structure described by ErH(SO4)2 crystallizes in the monoclinic P2_1/c space group. Er(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form ErO7 pentagonal bipyramids that share corners with three equivalent S(1)O4 tetrahedra and corners with four equivalent S(2)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one O(6) atom. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form SO4 tetrahedra that share corners with three equivalent Er(1)O7 pentagonal bipyramids. In the second S site, S(2) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form SO4 tetrahedra that share corners with four equivalent Er(1)O7 pentagonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Er(1) and one S(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Er(1) and one S(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Er(1) and one S(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Er(1) and one S(2) atom. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Er(1) and one S(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one H(1) and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one S(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one S(2) atom. is represented by the CIF file [CIF]
data_ErH(SO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.869
_cell_length_b   5.508
_cell_length_c   10.662
_cell_angle_alpha   74.578
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   615.309
_cell_formula_units_Z   4
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
  Er  Er0  1  0.167  0.264  0.848  1.0
  Er  Er1  1  0.667  0.736  0.652  1.0
  Er  Er2  1  0.333  0.264  0.348  1.0
  Er  Er3  1  0.833  0.736  0.152  1.0
  H  H4  1  0.024  0.849  0.395  1.0
  H  H5  1  0.524  0.151  0.105  1.0
  H  H6  1  0.476  0.849  0.895  1.0
  H  H7  1  0.976  0.151  0.605  1.0
  S  S8  1  0.682  0.324  0.995  1.0
  S  S9  1  0.182  0.676  0.505  1.0
  S  S10  1  0.545  0.790  0.320  1.0
  S  S11  1  0.955  0.790  0.820  1.0
  S  S12  1  0.045  0.210  0.180  1.0
  S  S13  1  0.455  0.210  0.680  1.0
  S  S14  1  0.818  0.324  0.495  1.0
  S  S15  1  0.318  0.676  0.005  1.0
  O  O16  1  0.789  0.448  0.597  1.0
  O  O17  1  0.510  0.447  0.691  1.0
  O  O18  1  0.185  0.502  0.634  1.0
  O  O19  1  0.685  0.498  0.866  1.0
  O  O20  1  0.010  0.553  0.809  1.0
  O  O21  1  0.655  0.853  0.235  1.0
  O  O22  1  0.575  0.776  0.456  1.0
  O  O23  1  0.044  0.760  0.488  1.0
  O  O24  1  0.289  0.552  0.903  1.0
  O  O25  1  0.759  0.103  0.003  1.0
  O  O26  1  0.955  0.996  0.230  1.0
  O  O27  1  0.455  0.004  0.270  1.0
  O  O28  1  0.259  0.897  0.497  1.0
  O  O29  1  0.845  0.853  0.735  1.0
  O  O30  1  0.544  0.240  0.012  1.0
  O  O31  1  0.075  0.224  0.044  1.0
  O  O32  1  0.925  0.776  0.956  1.0
  O  O33  1  0.456  0.760  0.988  1.0
  O  O34  1  0.155  0.147  0.265  1.0
  O  O35  1  0.741  0.103  0.503  1.0
  O  O36  1  0.545  0.996  0.730  1.0
  O  O37  1  0.045  0.004  0.770  1.0
  O  O38  1  0.241  0.897  0.997  1.0
  O  O39  1  0.711  0.448  0.097  1.0
  O  O40  1  0.956  0.240  0.512  1.0
  O  O41  1  0.425  0.224  0.544  1.0
  O  O42  1  0.345  0.147  0.765  1.0
  O  O43  1  0.990  0.447  0.191  1.0
  O  O44  1  0.315  0.502  0.134  1.0
  O  O45  1  0.815  0.498  0.366  1.0
  O  O46  1  0.490  0.553  0.309  1.0
  O  O47  1  0.211  0.552  0.403  1.0
[/CIF]
.