data_global
_amcsd_formula_title 'NH4H2AsO4'
loop_
_publ_author_name
'Khan A A'
'Baur W H'
_journal_name_full 'Acta Crystallographica, Section B'
_journal_volume 29 
_journal_year 1973
_journal_page_first 2721
_journal_page_last 2726
_publ_section_title
;
 Refinement of the crystal structures of ammonium dihydrogen phosphate and
 ammonium dihydrogen arsenate
 Note: known as ADA
;
_database_code_amcsd 0009494
_chemical_formula_sum 'As N O4 H6'
_cell_length_a 7.6998
_cell_length_b 7.6998
_cell_length_c 7.7158
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 457.446
_exptl_crystal_density_diffrn      2.308
_symmetry_space_group_name_H-M 'I -4 2 d'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/2-y,-x,3/4+z'
  '-y,1/2-x,1/4+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,1/2+y,1/4-z'
  '1/2-x,+y,3/4-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  '1/2+y,x,3/4+z'
  '+y,1/2+x,1/4+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
  'x,1/2-y,1/4-z'
  '1/2+x,-y,3/4-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
As   0.00000   0.00000   0.00000   1.00000 ?
N   0.00000   0.00000   0.50000   1.00000 ?
O   0.08690   0.15780   0.12330   1.00000 ?
H(n)   0.01400   0.12000   0.56700   1.00000   0.03040
H(o)   0.25000   0.19900   0.12500   0.50000   0.05826
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
As 0.01712 0.01712 0.02684 0.00000 0.00000 0.00000
N 0.03364 0.03364 0.02684 0.00000 0.00000 0.00000
O 0.02343 0.02643 0.04373 0.00571 -0.00843 -0.01445