data_global
_chemical_name_mineral 'Nontronite'
loop_
_publ_author_name
'Manceau A'
'Chateigner D'
'Gates W P'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 25 
_journal_year 1998
_journal_page_first 347
_journal_page_last 365
_publ_section_title
;
 Polarized EXAFS, distance-valence least-squares modelling (DVLS),
 and quantitative texture analysis approaches to the structural
 refinement of Garfield nontronite
;
_database_code_amcsd 0008146
_chemical_formula_sum 'Na.5 Fe2 (Si3.464 Al.536) O12 H2'
_cell_length_a 5.277
_cell_length_b 9.14
_cell_length_c 9.78
_cell_angle_alpha 90
_cell_angle_beta 101.0
_cell_angle_gamma 90
_cell_volume 463.040
_exptl_crystal_density_diffrn      3.077
_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
Na   0.50000   0.00000   0.50000   0.50000
Fe   0.00000   0.66700   0.00000   1.00000
Si   0.43100   0.32800   0.28800   0.86600
Al   0.43100   0.32800   0.28800   0.13400
O1   0.36400   0.31300   0.11500   1.00000
O2   0.48900   0.50000   0.33000   1.00000
O3   0.18600   0.73100   0.35300   1.00000
O-H4   0.39600   0.00000   0.11500   1.00000