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: Low pressure dickite at P = 0.1 MPa ; _database_code_amcsd 0003170 _chemical_formula_sum 'Si2 Al2 O9 H4' _cell_length_a 5.161 _cell_length_b 8.960 _cell_length_c 14.459 _cell_angle_alpha 90 _cell_angle_beta 96.77 _cell_angle_gamma 90 _cell_volume 663.959 _exptl_crystal_density_diffrn 2.583 _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 0.00880 0.40100 0.03240 0.01200 Si2 -0.00350 0.07220 0.03150 0.01000 Al1 0.91260 0.25230 0.22330 0.01600 Al2 0.41840 0.41760 0.22260 0.01800 O1 0.95620 0.23800 0.98640 0.01700 O2 0.25480 0.47140 0.98560 0.01800 O3 0.76360 0.50580 0.99910 0.01700 O4 0.07890 0.39080 0.14280 0.02100 O5 0.00250 0.08070 0.14430 0.01200 O-h1 0.58500 0.27470 0.14880 0.02200 O-h2 0.24320 0.27800 0.28660 0.01800 O-h3 0.25250 0.89320 0.28880 0.01500 O-h4 0.32340 0.58370 0.28630 0.02100 H1 0.57000 0.17300 0.15200 0.02600 H2 0.30700 0.26000 0.34600 0.02200 H3 0.25000 0.99000 0.30500 0.01800 H4 0.27000 0.58800 0.34200 0.02600