data_global _chemical_name_mineral 'Acuminite' loop_ _publ_author_name 'Krogh Andersen E' 'Ploug-Sorensen G' 'Leonardsen E' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 194 _journal_year 1991 _journal_page_first 221 _journal_page_last 227 _publ_section_title ; The structure of acuminite, a strontium aluminium fluoride mineral ; _database_code_amcsd 0010999 _chemical_compound_source 'Ivigtut, Greenland' _chemical_formula_sum 'Sr Al F4 (O2 H3)' _cell_length_a 13.223 _cell_length_b 5.175 _cell_length_c 14.251 _cell_angle_alpha 90 _cell_angle_beta 111.61 _cell_angle_gamma 90 _cell_volume 906.639 _exptl_crystal_density_diffrn 3.306 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Sr 0.83050 0.82320 0.15860 0.01406 Al 0.40240 0.40200 0.42030 0.00785 F1 0.80420 0.03710 0.30680 0.01229 F2 0.66480 0.09770 0.09300 0.01520 F3 0.02360 0.79100 0.15770 0.01381 F4 0.81740 0.96010 -0.01540 0.01343 O-H1 0.48910 0.70630 0.45570 0.04002 Wat2 0.89860 0.32510 0.16170 0.09372