data_global _chemical_name_mineral 'Fluorapatite' loop_ _publ_author_name 'Hughes J M' 'Cameron M' 'Mariano A N' _journal_name_full 'American Mineralogist' _journal_volume 76 _journal_year 1991 _journal_page_first 1165 _journal_page_last 1173 _publ_section_title ; Rare-earth-element ordering and structural variations in natural rare-earth-bearing apatites sample from the Oka carbonatite ; _database_code_amcsd 0001374 _chemical_formula_sum 'Ca4.825 Na.01 Ce.165 (P2.841 Si.159) O12.26 F.74 H.26' _cell_length_a 9.3995 _cell_length_b 9.3995 _cell_length_c 6.8941 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 527.494 _exptl_crystal_density_diffrn 3.272 _symmetry_space_group_name_H-M 'P 63/m' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x+y,-x,1/2-z' 'x-y,x,1/2+z' 'y,-x+y,-z' '-y,x-y,z' 'x,y,1/2-z' '-x,-y,1/2+z' 'x-y,x,-z' '-x+y,-x,z' '-y,x-y,1/2-z' 'y,-x+y,1/2+z' '-x,-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 Ca1 0.66667 0.33333 0.00110 0.98000 0.01131 Na1 0.66667 0.33333 0.00110 0.00500 0.01131 Ce1 0.66667 0.33333 0.00110 0.01500 0.01131 Ca2 0.99212 0.24276 0.25000 0.95500 0.01066 Ce2 0.99212 0.24276 0.25000 0.04500 0.01066 P 0.36875 0.39813 0.25000 0.94700 0.00722 Si 0.36875 0.39813 0.25000 0.05300 0.00722 O1 0.48490 0.32690 0.25000 1.00000 0.01216 O2 0.46590 0.58730 0.25000 1.00000 0.01368 O3 0.25730 0.34210 0.07050 1.00000 0.01672 F 0.00000 0.00000 0.25000 0.74000 0.03420 O-H 0.00000 0.00000 0.30200 0.13000 0.01646