data_global
_chemical_name_mineral 'Braunite'
loop_
_publ_author_name
'de Villiers J P R'
_journal_name_full 'American Mineralogist'
_journal_volume 60
_journal_year 1975
_journal_page_first 1098
_journal_page_last 1104
_publ_section_title
;
 The crystal structure of braunite with reference to its solid-solution behavior
;
_database_code_amcsd 484
_chemical_formula_sum 'Mn6.68 Mg.13 Ca.01 Fe.18 Si O12'
_cell_length_a 9.432
_cell_length_b 9.432
_cell_length_c 18.703
_cell_angle_alpha 90.0
_cell_angle_beta 90.0
_cell_angle_gamma 90.0
_cell_volume 1663.868
_exptl_crystal_density_diffrn  4.796
_symmetry_space_group_name_H-M 'I 41/a c d '
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/4-y,3/4-x,3/4+z'
  '3/4-y,1/4-x,1/4+z'
  '1/4+y,3/4+x,3/4-z'
  '3/4+y,1/4+x,1/4-z'
  '1/4+y,3/4-x,1/4-z'
  '3/4+y,1/4-x,3/4-z'
  '1/4-y,3/4+x,1/4+z'
  '3/4-y,1/4+x,3/4+z'
  '1/2+x,-y,z'
  '+x,1/2-y,1/2+z'
  '1/2-x,y,-z'
  '-x,1/2+y,1/2-z'
  '1/2+x,y,1/2-z'
  '+x,1/2+y,-z'
  '1/2-x,-y,1/2+z'
  '-x,1/2-y,+z'
  '1/4+y,1/4+x,1/4+z'
  '3/4+y,3/4+x,3/4+z'
  '1/4-y,1/4-x,1/4-z'
  '3/4-y,3/4-x,3/4-z'
  '1/4-y,1/4+x,3/4-z'
  '3/4-y,3/4+x,1/4-z'
  '1/4+y,1/4-x,3/4+z'
  '3/4+y,3/4-x,1/4+z'
  '-x,y,1/2+z'
  '1/2-x,1/2+y,+z'
  'x,-y,1/2-z'
  '1/2+x,1/2-y,-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mn1   0.0  0.25  0.125  0.86
Mg1   0.0  0.25  0.125  0.13
Ca1   0.0  0.25  0.125  0.01
Mn2   0.0  0.0  0.0  0.97
Fe1   0.0  0.0  0.0  0.03
Mn3   0.03365  0.0  0.25  0.97
Fe2   0.03365  0.0  0.25  0.03
Mn4   0.2325  0.4825  0.125  0.97
Fe3   0.2325  0.4825  0.125  0.03
Si   0.0  0.25  0.375  1.0
O1   0.1494  0.3549  0.0544  1.0
O2   0.1451  0.073  0.0568  1.0
O3   0.4219  0.134  0.0747  1.0
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
Mn1   0.0124  0.0124  0.0076  -0.0063  0.0  0.0
Mg1   0.0124  0.0124  0.0076  -0.0063  0.0  0.0
Ca1   0.0124  0.0124  0.0076  -0.0063  0.0  0.0
Mn2   0.0055  0.0064  0.0048  -0.0017  -0.0008  0.0001
Fe1   0.0055  0.0064  0.0048  -0.0017  -0.0008  0.0001
Mn3   0.0052  0.0061  0.0057  0.0  0.0  0.001
Fe2   0.0052  0.0061  0.0057  0.0  0.0  0.001
Mn4   0.0059  0.0059  0.0047  -0.0006  0.0004  -0.0004
Fe3   0.0059  0.0059  0.0047  -0.0006  0.0004  -0.0004
Si   0.0052  0.0052  0.0052  0.0  0.0  0.0
O1   0.0113  0.0082  0.0076  -0.0008  0.0006  -0.0013
O2   0.009  0.0074  0.0066  -0.0009  -0.0007  0.0007
O3   0.0104  0.0089  0.0081  0.0006  -0.0011  -0.0014