data_9001233 _chemical_name 'Hydroxylapatite' loop_ _publ_author_name 'Hughes J M' 'Cameron M' 'Crowley K D' _journal_name_full "American Mineralogist" _journal_volume 74 _journal_year 1989 _journal_page_first 870 _journal_page_last 876 _publ_section_title ; Structural variations in natural F, OH, and Cl apatites Locality: Holly Springs, Georgia, USA ; _chemical_formula_sum 'Ca5 P3 O13 H' _cell_length_a 9.4166 _cell_length_b 9.4166 _cell_length_c 6.8745 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 527.910 _symmetry_space_group_name_H-M 'P 63/m' loop_ _symmetry_equiv_pos_as_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_Uiso_or_equiv Ca1 0.66667 0.33333 0.00144 1.00000 ? Ca2 -0.00657 0.24706 0.25000 1.00000 ? P 0.36860 0.39866 0.25000 1.00000 ? O1 0.48500 0.32890 0.25000 1.00000 ? O2 0.46490 0.58710 0.25000 1.00000 ? O3 0.25800 0.34350 0.07030 1.00000 ? O(H) 0.00000 0.00000 0.19790 0.50000 ? H 0.00000 0.00000 0.04000 0.50000 0.04179