data_global _chemical_name_mineral 'Biotite' loop_ _publ_author_name 'Brigatti M F' 'Galli E' 'Poppi L' _journal_name_full 'American Mineralogist' _journal_volume 76 _journal_year 1991 _journal_page_first 1174 _journal_page_last 1183 _publ_section_title ; Effect of Ti substitution in biotite-M crystal chemistry Sample 17 from a quartz diorite, Capo Vaticano, Italy ; _database_code_amcsd 0001387 _chemical_formula_sum 'Si2.764 Al1.428 K.914 Ca.001 Na.022 Mg1.245 Cr.006 Fe1.296 Mn.009 Ti.198 O12' _cell_length_a 5.323 _cell_length_b 9.215 _cell_length_c 10.210 _cell_angle_alpha 90 _cell_angle_beta 100.14 _cell_angle_gamma 90 _cell_volume 492.993 _exptl_crystal_density_diffrn 3.081 _symmetry_space_group_name_H-M 'C 1 2/m 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' '-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 Si 0.07590 0.16640 0.22680 0.69100 Al 0.07590 0.16640 0.22680 0.30900 K 0.00000 0.50000 0.00000 0.91400 Ca 0.00000 0.50000 0.00000 0.00100 Na 0.00000 0.50000 0.00000 0.02200 Mg1 0.00000 0.00000 0.50000 0.41500 Al1 0.00000 0.00000 0.50000 0.06400 Cr1 0.00000 0.00000 0.50000 0.00200 Fe1 0.00000 0.00000 0.50000 0.43200 Mn1 0.00000 0.00000 0.50000 0.00300 Ti1 0.00000 0.00000 0.50000 0.06600 Mg2 0.00000 0.33270 0.50000 0.41500 Al2 0.00000 0.33270 0.50000 0.06400 Cr2 0.00000 0.33270 0.50000 0.00200 Fe2 0.00000 0.33270 0.50000 0.43200 Mn2 0.00000 0.33270 0.50000 0.00300 Ti2 0.00000 0.33270 0.50000 0.06600 O1 0.01450 0.00000 0.17120 1.00000 O2 0.32490 0.22980 0.16970 1.00000 O3 0.13020 0.16710 0.39040 1.00000 O4 0.12930 0.50000 0.39540 1.00000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Si 0.00779 0.01420 0.01791 -0.00049 0.00534 0.00047 Al 0.00779 0.01420 0.01791 -0.00049 0.00534 0.00047 K 0.02949 0.04087 0.05424 0.00000 0.01334 0.00000 Ca 0.02949 0.04087 0.05424 0.00000 0.01334 0.00000 Na 0.02949 0.04087 0.05424 0.00000 0.01334 0.00000 Mg1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Al1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Cr1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Fe1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Mn1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Ti1 0.01015 0.00989 0.01689 0.00000 0.00267 0.00000 Mg2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 Al2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 Cr2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 Fe2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 Mn2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 Ti2 0.01043 0.00946 0.01586 0.00000 0.00534 0.00000 O1 0.02615 0.02108 0.05015 0.00000 0.00934 0.00000 O2 0.01836 0.02753 0.04759 -0.00196 0.00960 0.00047 O3 0.00918 0.01420 0.01177 -0.00342 0.00374 0.00375 O4 0.02253 0.01936 0.00205 0.00000 0.00000 0.00000