data_global
_chemical_name_mineral 'Cordierite'
loop_
_publ_author_name
'Koepke J'
'Schulz H'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 13 
_journal_year 1986
_journal_page_first 165
_journal_page_last 173
_publ_section_title
;
 Single crystal structure investigations under high-pressure of the
 mineral cordierite with an improved high-pressure cell
 Sample: P = 0.1 MPa
;
_database_code_amcsd 0007383
_chemical_compound_source 'Zabargad island, Red Sea'
_chemical_formula_sum 'Mg2 Al4 Si5 O18'
_cell_length_a 17.071
_cell_length_b 9.715
_cell_length_c 9.344
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 1549.653
_exptl_crystal_density_diffrn      2.507
_symmetry_space_group_name_H-M 'C c c m'
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'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-z'
  '-x,y,1/2+z'
  '1/2-x,1/2+y,1/2+z'
  'x,-y,1/2-z'
  '1/2+x,1/2-y,1/2-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_U_iso_or_equiv
Mg   0.16248   0.50000   0.25000   0.00880
Al11   0.25000   0.25000   0.25050   0.00750
Si16   0.00000   0.50000   0.25000   0.00670
Si21   0.19281   0.07820   0.00000   0.00530
Al26   0.05060   0.30850   0.00000   0.00620
Si23  -0.13544   0.23760   0.00000   0.00600
O11   0.24680   0.10290   0.14070   0.00830
O16   0.06250   0.41560   0.15060   0.00840
O13  -0.17330   0.31000   0.14130   0.00770
O21   0.12260   0.18460   0.00000   0.01120
O26  -0.04330   0.24910   0.00000   0.01170
O23  -0.16380   0.08030   0.00000   0.01350