data_1011153
_chemical_name_systematic
;
Dialuminium phyllo-tetrasilicate dihydroxide
;
_chemical_name_mineral             'Pyrophyllite 2M1'
_chemical_compound_source          'from Tres Cerritos, Mariposa Co., Calif.'
_chemical_formula_structural       'Al2 (Si4 O10) (O H)2'
_chemical_formula_sum              'H2 Al2 O12 Si4'
_publ_section_title
;
The crystal structures of talc and pyrophyllite.
;
_publ_author_name                  'Gruner, J W'
_journal_name_full
;
Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik,
Kristallchemie (-144,1977)
;
_journal_coden_ASTM                ZEKGAX
_journal_volume                    88
_journal_year                      1934
_journal_page_first                412
_journal_page_last                 419
_cell_length_a                     5.14(2)
_cell_length_b                     8.90(2)
_cell_length_c                     18.549990000(29999998)
_cell_angle_alpha                  90
_cell_angle_beta                   99.92(8)
_cell_angle_gamma                  90
_cell_volume                       835.9
_cell_formula_units_Z              4
_exptl_crystal_density_meas        2.8
_symmetry_space_group_name_H-M     'C 1 2/c 1'
_symmetry_Int_Tables_number        15
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,y,1/2-z'
  '-x,-y,-z'
  'x,-y,1/2+z'
  '1/2+x,1/2+y,z'
  '1/2-x,1/2+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
  Al3+   3.000
  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
  Al1   Al3+   8 f 0. 0.333 0. 1.  0 d
  O1    O2-    8 f 0.203 0.5 0.058 1.  0 d
  O2    O2-    8 f 0.203 0.167 0.058 1.  0 d
  O3    O2-    8 f 0.203 -0.167 0.058 1.  1 d
  O4    O2-    8 f 0.025 0.083 0.176 1.  0 d
  O5    O2-    8 f -0.475 0.083 0.176 1.  0 d
  O6    O2-    8 f 0.275 0.333 0.176 1.  0 d
  Si1   Si4+   8 f -0.239 0. 0.143 1.  0 d
  Si2   Si4+   8 f 0.261 0.167 0.143 1.  0 d
  H1    H1+    8 f -1. -1. -1. 1.  0 dum