data_global
_chemical_name_mineral 'Dickite'
loop_
_publ_author_name
'Dera P'
'Prewitt C T'
'Japel S'
'Bish D L'
'Johnston C T'
_journal_name_full 'American Mineralogist'
_journal_volume 88 
_journal_year 2003
_journal_page_first 1428
_journal_page_last 1435
_publ_section_title
;
 Pressure-controlled polytypism in hydrous layered materials
 Sample: High pressure dickite at P = 4.1 GPa
;
_database_code_amcsd 0003171
_chemical_formula_sum 'Si2 Al2 O9 H4'
_cell_length_a 5.082
_cell_length_b 8.757
_cell_length_c 13.771
_cell_angle_alpha 90
_cell_angle_beta 89.60
_cell_angle_gamma 90
_cell_volume 612.837
_exptl_crystal_density_diffrn      2.798
_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_U_iso_or_equiv
Si1   0.04600   0.48800   0.03800   0.00500
Si2   0.03250   0.15890   0.03700   0.00500
Al1   0.87900   0.33520   0.23300   0.00500
Al2   0.38550   0.50010   0.23400   0.00500
O1   0.98700   0.32400   0.98600 ?
O2   0.31600   0.55000  -0.00900   0.00400
O3   0.82700   0.60600  -0.00400   0.00700
O4   0.07100   0.47800   0.15500   0.00800
O5   0.00200   0.17000   0.15500   0.00600
O-h1   0.57800   0.36000   0.16100   0.00300
O-h2   0.19700   0.35300   0.30400   0.00500
O-h3   0.19000   0.98400   0.30300   0.01000
O-h4   0.26200   0.66600   0.30100   0.01100
H1   0.49640   0.25560   0.14210 ?
H2   0.23490   0.28210   0.35110 ?
H3   0.25180   0.01700   0.35570 ?
H4   0.23290   0.63450   0.37010 ?