data_global _chemical_name_mineral 'Ice III' loop_ _publ_author_name 'McFarlan R' _journal_name_full 'Journal of Chemical Physics' _journal_volume 4 _journal_year 1936 _journal_page_first 253 _journal_page_last 259 _publ_section_title ; The Structure of Ice III _cod_database_code 1011024 ; _database_code_amcsd 0017931 _chemical_formula_sum 'O4 H7' _cell_length_a 10.2 _cell_length_b 5.87 _cell_length_c 7.17 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 429.297 _exptl_crystal_density_diffrn 1.099 _symmetry_space_group_name_H-M 'I b a m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,-y,1/2+z' '1/2+x,1/2-y,+z' '-x,y,1/2-z' '1/2-x,1/2+y,-z' '-x,y,1/2+z' '1/2-x,1/2+y,+z' 'x,-y,1/2-z' '1/2+x,1/2-y,-z' 'x,y,-z' '1/2+x,1/2+y,1/2-z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z O1 0.12600 0.21800 0.06250 H1 0.25000 0.25000 0.00000 H2 0.12600 0.00000 0.00000 H3 0.00000 0.21800 0.00000 H4 0.00000 0.50000 0.25000