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