data_global
_chemical_name_mineral 'Cahnite'
loop_
_publ_author_name
'Prewitt C T'
'Buerger M J'
_journal_name_full 'American Mineralogist'
_journal_volume 46 
_journal_year 1961
_journal_page_first 1077
_journal_page_last 1085
_publ_section_title
;
 The crystal structure of cahnite, Ca2BAsO4(OH)4
;
_database_code_amcsd 0000097
_chemical_compound_source 'Franklin, New Jersey, USA'
_chemical_formula_sum 'As B Ca2 O8 H4'
_cell_length_a 7.11
_cell_length_b 7.11
_cell_length_c 6.20
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 313.423
_exptl_crystal_density_diffrn      3.157
_symmetry_space_group_name_H-M 'I -4'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
As   0.00000   0.00000   0.00000
B   0.00000   0.50000   0.25000
Ca1   0.00000   0.00000   0.50000
Ca2   0.00000   0.50000   0.75000
O1   0.17800   0.05400   0.16700
O-H2   0.16000   0.44400   0.11400