data_global
_chemical_name_mineral 'Bracewellite'
loop_
_publ_author_name
'Milton C'
'Appleman D E'
'Appleman M H'
'Chao E C T'
'Cuttita F'
'Dinnin J I'
'Dwornik E J'
'Ingram B L'
'Rose H J'
_journal_name_full 'U.S. Geological Survey Professional Paper'
_journal_volume 887 
_journal_year 1976
_journal_page_first 1
_journal_page_last 29
_publ_section_title
;
 Merumite, a complex assemblage of chromium minerals from Guyana
;
_database_code_amcsd 0015707
_chemical_compound_source 'Guyana'
_chemical_formula_sum 'Cr O2 H'
_cell_length_a 4.492
_cell_length_b 9.860
_cell_length_c 2.974
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 131.722
_exptl_crystal_density_diffrn      4.286
_symmetry_space_group_name_H-M 'P b n m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Cr  -0.05200   0.14500   0.25000
O1   0.30100  -0.19700   0.25000
O-H2  -0.19800  -0.05400   0.25000