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 10 from a lamproite rock, Fortuna, Spain ; _database_code_amcsd 0001382 _chemical_formula_sum 'Si2.932 Al1.161 K.958 Ca.004 Na.016 Mg1.602 Cr.054 Fe.588 Mn.03 Ti.522 O12' _cell_length_a 5.322 _cell_length_b 9.228 _cell_length_c 10.102 _cell_angle_alpha 90 _cell_angle_beta 100.25 _cell_angle_gamma 90 _cell_volume 488.206 _exptl_crystal_density_diffrn 3.026 _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 0.07430 0.16700 0.22320 0.73300 Al 0.07430 0.16700 0.22320 0.26700 K 0.00000 0.50000 0.00000 0.95800 Ca 0.00000 0.50000 0.00000 0.00400 Na 0.00000 0.50000 0.00000 0.01600 Mg1 0.00000 0.00000 0.50000 0.53400 Al1 0.00000 0.00000 0.50000 0.03100 Cr1 0.00000 0.00000 0.50000 0.01800 Fe1 0.00000 0.00000 0.50000 0.19600 Mn1 0.00000 0.00000 0.50000 0.01000 Ti1 0.00000 0.00000 0.50000 0.17400 Mg2 0.00000 0.33530 0.50000 0.53400 Al2 0.00000 0.33530 0.50000 0.03100 Cr2 0.00000 0.33530 0.50000 0.01800 Fe2 0.00000 0.33530 0.50000 0.19600 Mn2 0.00000 0.33530 0.50000 0.01000 Ti2 0.00000 0.33530 0.50000 0.17400 O1 0.02910 0.00000 0.16730 1.00000 O2 0.31870 0.23680 0.16630 1.00000 O3 0.13210 0.16870 0.39070 1.00000 O4 0.13080 0.50000 0.40070 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 0.00931 0.00863 0.02002 -0.00024 0.00211 -0.00046 Al 0.00931 0.00863 0.02002 -0.00024 0.00211 -0.00046 K 0.03265 0.03020 0.03755 0.00000 0.00501 0.00000 Ca 0.03265 0.03020 0.03755 0.00000 0.00501 0.00000 Na 0.03265 0.03020 0.03755 0.00000 0.00501 0.00000 Mg1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Al1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Cr1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Fe1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Mn1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Ti1 0.01125 0.00949 0.02503 0.00000 0.00343 0.00000 Mg2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 Al2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 Cr2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 Fe2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 Mn2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 Ti2 0.00987 0.01639 0.02203 0.00000 0.00343 0.00000 O1 0.03418 0.01467 0.02353 0.00000 0.00053 0.00000 O2 0.02070 0.02761 0.01952 -0.00490 0.00132 -0.00139 O3 0.01389 0.00949 0.02103 -0.00098 0.00237 -0.00046 O4 0.00903 0.01294 0.02253 0.00000 0.00686 0.00000