data_global
_chemical_name_mineral 'Biotite'
loop_
_publ_author_name
'Bigi S'
'Brigatti M F'
_journal_name_full 'American Mineralogist'
_journal_volume 79 
_journal_year 1994
_journal_page_first 63
_journal_page_last 72
_publ_section_title
;
 Crystal chemistry and microstructures of plutonic biotite
 Sample 2M1 from Valle del Cervo syenitic complex
;
_database_code_amcsd 0001634
_chemical_formula_sum '(Si2.784 Al1.216) Fe1.215 Mg1.545 Mn.018 Ti.225 K.946 Na.032 O12'
_cell_length_a 5.339
_cell_length_b 9.249
_cell_length_c 20.196
_cell_angle_alpha 90
_cell_angle_beta 95.06
_cell_angle_gamma 90
_cell_volume 993.400
_exptl_crystal_density_diffrn      3.062
_symmetry_space_group_name_H-M 'C 1 2/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-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
SiT1   0.46150   0.24980   0.13700   0.69600
AlT1   0.46150   0.24980   0.13700   0.30400
SiT2   0.96360   0.41660   0.13710   0.69600
AlT2   0.96360   0.41660   0.13710   0.30400
Fe1   0.75000   0.25000   0.00000   0.40500
Mg1   0.75000   0.25000   0.00000   0.51500
Mn1   0.75000   0.25000   0.00000   0.00600
Ti1   0.75000   0.25000   0.00000   0.07500
Fe2   0.24730   0.08250   0.00000   0.40500
Mg2   0.24730   0.08250   0.00000   0.51500
Mn2   0.24730   0.08250   0.00000   0.00600
Ti2   0.24730   0.08250   0.00000   0.07500
K   0.00000   0.08520   0.25000   0.94600
Na   0.00000   0.08520   0.25000   0.03200
O11   0.73850   0.31760   0.16560   1.00000
O21   0.23680   0.34780   0.16650   1.00000
O22   0.44180   0.08440   0.16620   1.00000
O31   0.43240   0.23760   0.05500   1.00000
O32   0.93590   0.40470   0.05500   1.00000
O4   0.93510   0.06950   0.05180   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
SiT1 0.01060 0.00997 0.01435 0.00075 0.00108 0.00094
AlT1 0.01060 0.00997 0.01435 0.00075 0.00108 0.00094
SiT2 0.01089 0.01040 0.01435 0.00125 0.00108 0.00094
AlT2 0.01089 0.01040 0.01435 0.00125 0.00108 0.00094
Fe1 0.00989 0.01343 0.01640 -0.00199 0.00163 -0.00377
Mg1 0.00989 0.01343 0.01640 -0.00199 0.00163 -0.00377
Mn1 0.00989 0.01343 0.01640 -0.00199 0.00163 -0.00377
Ti1 0.00989 0.01343 0.01640 -0.00199 0.00163 -0.00377
Fe2 0.01605 0.01430 0.01640 -0.00075 0.00217 -0.00283
Mg2 0.01605 0.01430 0.01640 -0.00075 0.00217 -0.00283
Mn2 0.01605 0.01430 0.01640 -0.00075 0.00217 -0.00283
Ti2 0.01605 0.01430 0.01640 -0.00075 0.00217 -0.00283
K 0.03410 0.03510 0.04306 0.00000 0.00379 0.00000
Na 0.03410 0.03510 0.04306 0.00000 0.00379 0.00000
O11 0.01848 0.02210 0.02255 -0.00374 0.00217 -0.00094
O21 0.02049 0.01907 0.02255 0.00249 0.00000 -0.00094
O22 0.02364 0.01647 0.02255 0.00174 0.00379 -0.00283
O31 0.01175 0.00260 0.01025 -0.00050 0.00000 -0.00094
O32 0.01404 0.00953 0.01230 0.00050 0.00217 -0.00189
O4 0.01476 0.00823 0.01845 0.00249 0.00271 -0.00471