data_global
_chemical_name_mineral 'Vermiculite'
loop_
_publ_author_name
'Gruner J W'
_journal_name_full 'American Mineralogist'
_journal_volume 19 
_journal_year 1934
_journal_page_first 557
_journal_page_last 575
_publ_section_title
;
 The structures of vermiculites and their collapse by dehydration
;
_database_code_amcsd 0000012
_chemical_compound_source 'Structure results from data of many samples'
_chemical_formula_sum 'Mg3 Si4 (O12 H2)'
_cell_length_a 5.31
_cell_length_b 9.20
_cell_length_c 28.46
_cell_angle_alpha 90
_cell_angle_beta 97.14
_cell_angle_gamma 90
_cell_volume 1379.547
_exptl_crystal_density_diffrn      1.826
_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
Mg1   0.00000   0.00000   0.00000
Mg2   0.00000   0.33333   0.00000
Mg3   0.00000   0.66667   0.00000
Si1   0.39700   0.00000   0.09400
Si2   0.89700   0.16667   0.09400
Si3   0.60300   0.00000   0.40600
Si4   0.10300   0.16667   0.40600
O-H1   0.85800   0.83333   0.03900
O-H2   0.14200   0.83333   0.46100
O1   0.85800   0.50000   0.03900
O2   0.85800   0.16667   0.03900
O3   0.16100   0.08333   0.11500
O4   0.66100   0.08333   0.11500
O5   0.91100   0.33333   0.11500
O6   0.83900   0.08333   0.38500
O7   0.33900   0.08333   0.38500
O8   0.08900   0.33333   0.38500
O9   0.14200   0.50000   0.46100
O10   0.14200   0.16667   0.46100