The compound described by NH4H2AsO4 crystallizes in the tetragonal I-42d space group. The structure consists of four ammonium molecules inside a H2AsO4 framework. In the H2AsO4 framework, As(1) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. H(2) is bonded in a linear geometry to two equivalent O(1) atoms. O(1) is bonded in a bent 120 degrees geometry to one As(1) and one H(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_AsH6NO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.687
_cell_length_b   6.687
_cell_length_c   6.687
_cell_angle_alpha   116.537
_cell_angle_beta   106.058
_cell_angle_gamma   106.058
_symmetry_Int_Tables_number   1
_cell_volume   227.485
_cell_formula_units_Z   2
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
  As  As0  1  0.500  0.750  0.250  1.0
  As  As1  1  0.000  0.000  0.000  1.0
  H  H2  1  0.635  0.256  0.703  1.0
  H  H3  1  0.947  0.494  0.629  1.0
  H  H4  1  0.365  0.068  0.621  1.0
  H  H5  1  0.053  0.682  0.547  1.0
  H  H6  1  0.553  0.297  0.932  1.0
  H  H7  1  0.135  0.453  0.506  1.0
  H  H8  1  0.447  0.379  0.744  1.0
  H  H9  1  0.865  0.371  0.318  1.0
  H  H10  1  0.891  0.016  0.625  1.0
  H  H11  1  0.109  0.734  0.125  1.0
  H  H12  1  0.391  0.375  0.266  1.0
  H  H13  1  0.609  0.875  0.984  1.0
  N  N14  1  0.500  0.250  0.750  1.0
  N  N15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.745  0.037  0.491  1.0
  O  O17  1  0.954  0.713  0.958  1.0
  O  O18  1  0.255  0.746  0.292  1.0
  O  O19  1  0.046  0.004  0.759  1.0
  O  O20  1  0.546  0.509  0.254  1.0
  O  O21  1  0.245  0.241  0.287  1.0
  O  O22  1  0.454  0.708  0.963  1.0
  O  O23  1  0.755  0.042  0.996  1.0
[/CIF]
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The compound described by NH4H2AsO4 crystallizes in the tetragonal I-42d space group. The structure consists of four ammonium molecules inside a H2AsO4 framework. In the H2AsO4 framework, As(1) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. H(2) is bonded in a linear geometry to two equivalent O(1) atoms. O(1) is bonded in a bent 120 degrees geometry to one As(1) and one H(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_AsH6NO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.687
_cell_length_b   6.687
_cell_length_c   6.687
_cell_angle_alpha   116.537
_cell_angle_beta   106.058
_cell_angle_gamma   106.058
_symmetry_Int_Tables_number   1
_cell_volume   227.485
_cell_formula_units_Z   2
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
  As  As0  1  0.500  0.750  0.250  1.0
  As  As1  1  0.000  0.000  0.000  1.0
  H  H2  1  0.635  0.256  0.703  1.0
  H  H3  1  0.947  0.494  0.629  1.0
  H  H4  1  0.365  0.068  0.621  1.0
  H  H5  1  0.053  0.682  0.547  1.0
  H  H6  1  0.553  0.297  0.932  1.0
  H  H7  1  0.135  0.453  0.506  1.0
  H  H8  1  0.447  0.379  0.744  1.0
  H  H9  1  0.865  0.371  0.318  1.0
  H  H10  1  0.891  0.016  0.625  1.0
  H  H11  1  0.109  0.734  0.125  1.0
  H  H12  1  0.391  0.375  0.266  1.0
  H  H13  1  0.609  0.875  0.984  1.0
  N  N14  1  0.500  0.250  0.750  1.0
  N  N15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.745  0.037  0.491  1.0
  O  O17  1  0.954  0.713  0.958  1.0
  O  O18  1  0.255  0.746  0.292  1.0
  O  O19  1  0.046  0.004  0.759  1.0
  O  O20  1  0.546  0.509  0.254  1.0
  O  O21  1  0.245  0.241  0.287  1.0
  O  O22  1  0.454  0.708  0.963  1.0
  O  O23  1  0.755  0.042  0.996  1.0
[/CIF]
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