data_global
_chemical_name_mineral 'Vermiculite'
loop_
_publ_author_name
'Mathieson A M'
'Walker G F'
_journal_name_full 'American Mineralogist'
_journal_volume 39
_journal_year 1954
_journal_page_first 231
_journal_page_last 255
_publ_section_title
;
 Crystal structure of magnesium-vermiculite
;
_database_code_amcsd 63
_chemical_formula_sum 'Mg1.338 Fe.24 Al.721 Si1.36 O9 H3'
_cell_length_a 5.33
_cell_length_b 9.18
_cell_length_c 28.9
_cell_angle_alpha 90.0
_cell_angle_beta 97.0
_cell_angle_gamma 90.0
_cell_volume 1403.52
_exptl_crystal_density_diffrn  1.186
_symmetry_space_group_name_H-M 'C 1 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'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mg1   0.0  0.0  0.0  0.393
Fe1   0.0  0.0  0.0  0.08
Al1   0.0  0.0  0.0  0.027
Mg2   0.0  0.333  0.0  0.393
Fe2   0.0  0.333  0.0  0.08
Al2   0.0  0.333  0.0  0.027
Mg3   0.0  0.667  0.0  0.393
Fe3   0.0  0.667  0.0  0.08
Al3   0.0  0.667  0.0  0.027
Si1   0.397  0.0  0.096  0.68
Al4   0.397  0.0  0.096  0.32
Si2   0.397  0.333  0.097  0.68
Al5   0.397  0.333  0.097  0.32
Mg4   0.5  0.0  0.25  0.053
Mg5   0.5  0.333  0.25  0.053
Mg6   0.5  0.667  0.25  0.053
O1   0.358  0.0  0.037  1.0
O2   0.358  0.333  0.037  1.0
O3   0.358  0.667  0.037  1.0
O4   0.147  0.404  0.114  1.0
O5   0.147  0.929  0.114  1.0
O6   0.434  0.167  0.114  1.0
O-H7   0.16  -0.019  0.213  1.0
O-H8   0.16  0.352  0.213  1.0
O-H9   0.105  0.667  0.213  1.0