#------------------------------------------------------------------------------
#$Date: 2012-02-28 14:14:52 +0200 (Tue, 28 Feb 2012) $
#$Revision: 35911 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/00/00/1000036.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_1000036

_chemical_name_systematic          'Trimagnesium dihydrogen phyllo-silicate'
_chemical_name_mineral             'Vermiculite'
_chemical_formula_structural       'Mg3 Si4 O10 (O H)2'
_chemical_formula_sum              'H2 Mg3 O12 Si4'

_publ_section_title
;
Crystal structure of vermiculites and mixed vermiculite-chlorites
;
loop_
_publ_author_name
  'Hendricks, S B'
  'Jefferson, M E'
_journal_name_full                 'American Mineralogist'
_journal_coden_ASTM                AMMIAY
_journal_volume                    23
_journal_year                      1938
_journal_page_first                851
_journal_page_last                 862

_cell_length_a                     5.33(5)
_cell_length_b                     9.18(5)
_cell_length_c                     28.85(10)
_cell_angle_alpha                  90
_cell_angle_beta                   93.25(25)
_cell_angle_gamma                  90
_cell_volume                       1409.3
_cell_formula_units_Z              4

_symmetry_space_group_name_H-M     'C 1 c 1'
_symmetry_Int_Tables_number        9
_symmetry_cell_setting             monoclinic

loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2+y,z'
  '1/2+x,1/2-y,1/2+z'

loop_
_atom_type_symbol
_atom_type_oxidation_number
  Mg2+   2.000
  O2-   -2.000
  Si4+   4.000
  H1+    1.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Mg1   Mg2+   4 a 0. 0. 0. 1.  0 d
  Mg2   Mg2+   4 a 0. 0.3333 0. 1.  0 d
  Mg3   Mg2+   4 a 0. 0.6667 0. 1.  0 d
  O1    O2-    4 a 0.18 0.5 0.04 1.  1 d
  O2    O2-    4 a -0.18 0.8333 -0.04 1.  1 d
  O3    O2-    4 a 0.18 0.8333 0.04 1.  0 d
  O4    O2-    4 a -0.18 0.5 -0.04 1.  0 d
  O5    O2-    4 a 0.18 0.1667 0.04 1.  0 d
  O6    O2-    4 a -0.18 0.1667 -0.04 1.  0 d
  O7    O2-    4 a -0.048 0.75 0.115 1.  0 d
  O8    O2-    4 a 0.048 0.5833 -0.115 1.  0 d
  O9    O2-    4 a 0.452 0.75 0.115 1.  0 d
  O10   O2-    4 a -0.452 0.5833 -0.115 1.  0 d
  O11   O2-    4 a 0.202 0. 0.115 1.  0 d
  O12   O2-    4 a -0.202 0.3333 -0.115 1.  0 d
  Si1   Si4+   4 a 0.196 0.8333 0.095 1.  0 d
  Si2   Si4+   4 a -0.196 0.5 -0.095 1.  0 d
  Si3   Si4+   4 a -0.304 0.6667 0.095 1.  0 d
  Si4   Si4+   4 a 0.304 0.6667 -0.095 1.  0 d
  H1    H1+    4 a -1. -1. -1. 2.  0 dum



_cod_database_code 1000036