data_global _chemical_name_mineral 'Phlogopite' loop_ _publ_author_name 'Hendricks S B' 'Jefferson M E' _journal_name_full 'American Mineralogist' _journal_volume 24 _journal_year 1939 _journal_page_first 729 _journal_page_last 771 _publ_section_title ; Polymorphism of the micas with optical measurements Note: Biotite group ; _database_code_amcsd 26 _chemical_formula_sum 'K Mg3 (Si3 Al) O11 (F H)' _cell_length_a 5.3 _cell_length_b 5.3 _cell_length_c 30.0 _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 120.0 _cell_volume 729.8 _exptl_crystal_density_diffrn 2.862 _symmetry_space_group_name_H-M 'P 31 1 2' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x+y,y,1/3-z' '-y,x-y,1/3+z' '-y,-x,2/3-z' '-x+y,-x,2/3+z' 'x,x-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy K 0.11111 0.0556 0.0 1.0 Mg1 0.11111 0.22222 0.16667 1.0 Mg3 -0.22222 -0.44444 0.16667 1.0 Mg3 0.44444 0.88889 0.16667 1.0 Si1 -0.22 0.22 0.078 0.75 Si2 0.44 -0.44 0.078 0.75 Al1 -0.22 0.22 0.078 0.25 Al2 0.44 -0.44 0.078 0.25 O1 0.11 0.39 0.06 1.0 O2 -0.39 -0.11 0.06 1.0 O3 -0.39 0.39 0.06 1.0 O4 -0.22 0.22 0.13 1.0 O5 0.44 -0.44 0.13 1.0 O-H 0.11 -0.11 0.13 0.5 F 0.11 -0.11 0.13 0.5