data_global _chemical_name_mineral 'Montebrasite' loop_ _publ_author_name 'Groat L A' 'Raudsepp M' 'Hawthorne F C' 'Ercit T S' 'Sherriff B L' 'Hartman J S' _journal_name_full 'American Mineralogist' _journal_volume 75 _journal_year 1990 _journal_page_first 992 _journal_page_last 1008 _publ_section_title ; The amblygonite-montebrasite series: Characterization by single-crystal structure refinement, infrared spectroscopy and multinuclear MAS-NMR spectroscopy sample AF-46 ; _database_code_amcsd 0001324 _chemical_formula_sum 'P Al O4.5 (F.5 Li) H.5' _cell_length_a 6.6782 _cell_length_b 7.7159 _cell_length_c 6.949 _cell_angle_alpha 90.82 _cell_angle_beta 117.66 _cell_angle_gamma 91.22 _cell_volume 316.959 _exptl_crystal_density_diffrn 3.078 _symmetry_space_group_name_H-M 'C -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,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_occupancy _atom_site_U_iso_or_equiv P -0.01457 0.34047 0.26018 1.00000 0.00570 Al1 0.00000 0.00000 0.00000 1.00000 0.00600 Al2 0.00000 0.00000 0.50000 1.00000 0.00570 O1 -0.31600 0.01660 -0.15000 1.00000 0.00860 O2 0.29840 0.05970 0.58290 1.00000 0.00900 O3 0.09980 -0.22220 -0.38600 1.00000 0.00810 O4 0.02600 0.23320 0.09640 1.00000 0.01010 O-H 0.03040 0.08500 -0.23520 0.50000 0.00920 F 0.03040 0.08500 -0.23520 0.50000 0.00920 Li1 0.05000 -0.31500 0.26300 0.50000 0.02510 Li2 0.06100 -0.32900 0.31000 0.50000 0.02510