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 12 from a lamproite rock, Jummilla, Spain ; _database_code_amcsd 0001384 _chemical_formula_sum 'Si2.904 Al1.135 (K.947 Ca.002 Na.051) Mg2.088 Cr.054 Fe.498 Mn.018 Ti.267 O12' _cell_length_a 5.314 _cell_length_b 9.190 _cell_length_c 10.160 _cell_angle_alpha 90 _cell_angle_beta 100.18 _cell_angle_gamma 90 _cell_volume 488.359 _exptl_crystal_density_diffrn 2.976 _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 0.07500 0.16680 0.22580 0.72600 Al 0.07500 0.16680 0.22580 0.27400 K 0.00000 0.50000 0.00000 0.94700 Ca 0.00000 0.50000 0.00000 0.00200 Na 0.00000 0.50000 0.00000 0.05100 Mg1 0.00000 0.00000 0.50000 0.69600 Al1 0.00000 0.00000 0.50000 0.01300 Cr1 0.00000 0.00000 0.50000 0.01800 Fe1 0.00000 0.00000 0.50000 0.16600 Mn1 0.00000 0.00000 0.50000 0.00600 Ti1 0.00000 0.00000 0.50000 0.08900 Mg2 0.00000 0.33570 0.50000 0.69600 Al2 0.00000 0.33570 0.50000 0.01300 Cr2 0.00000 0.33570 0.50000 0.01800 Fe2 0.00000 0.33570 0.50000 0.16600 Mn2 0.00000 0.33570 0.50000 0.00600 Ti2 0.00000 0.33570 0.50000 0.08900 O1 0.02140 0.00000 0.16860 1.00000 O2 0.32250 0.23300 0.16770 1.00000 O3 0.13070 0.16740 0.39100 1.00000 O4 0.13110 0.50000 0.39950 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 0.00984 0.01626 0.01722 0.00024 0.00291 0.00047 Al 0.00984 0.01626 0.01722 0.00024 0.00291 0.00047 K 0.03312 0.03979 0.04053 0.00000 0.00715 0.00000 Ca 0.03312 0.03979 0.04053 0.00000 0.00715 0.00000 Na 0.03312 0.03979 0.04053 0.00000 0.00715 0.00000 Mg1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Al1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Cr1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Fe1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Mn1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Ti1 0.01178 0.01968 0.02280 0.00000 0.00450 0.00000 Mg2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 Al2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 Cr2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 Fe2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 Mn2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 Ti2 0.01095 0.02310 0.02026 0.00000 0.00397 0.00000 O1 0.02800 0.02268 0.02178 0.00000 0.00371 0.00000 O2 0.01913 0.03081 0.02229 -0.00609 0.00556 -0.00186 O3 0.01123 0.02054 0.01824 0.00024 0.00318 -0.00047 O4 0.00970 0.02097 0.01976 0.00000 0.00371 0.00000