data_9000216
_chemical_name 'Buergerite'
loop_
_publ_author_name
'Tippe A'
'Hamilton W C'
_journal_name_full "American Mineralogist"
_journal_volume 56
_journal_year 1971
_journal_page_first 101
_journal_page_last 113
_publ_section_title
;
 A neutron-diffraction study of the ferric tourmaline, buergerite
;
_chemical_formula_sum 'Na B3 Fe3 Si6 Al6 F O30 H3'
_cell_length_a 15.869
_cell_length_b 15.869
_cell_length_c 7.188
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1567.609
_symmetry_space_group_name_H-M 'R 3 m'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'x,x-y,z'
  '2/3+x,1/3+x-y,1/3+z'
  '1/3+x,2/3+x-y,2/3+z'
  '-y,-x,z'
  '2/3-y,1/3-x,1/3+z'
  '1/3-y,2/3-x,2/3+z'
  '-x+y,y,z'
  '2/3-x+y,1/3+y,1/3+z'
  '1/3-x+y,2/3+y,2/3+z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_Uiso_or_equiv
Na   0.00000   0.00000   0.21186 ?
B   0.11001  -0.11001   0.45172 ?
Fe  -0.06614   0.06614   0.62217 ?
Si   0.19171   0.19087   0.00000 ?
Al   0.29925   0.25919   0.60450 ?
F   0.00000   0.00000   0.76850 ?
O2   0.06042  -0.06042   0.48532 ?
O3  -0.13205   0.13205   0.52026 ?
O4   0.09463  -0.09463   0.07612 ?
O5  -0.09117   0.09117   0.08362 ?
O6   0.19320   0.18712   0.77538 ?
O7   0.28708   0.28592   0.07513 ?
O8   0.20925   0.26971   0.43868 ?
H  -0.13130   0.13130   0.38890   0.03040