data_global _chemical_name_mineral 'Gypsum' loop_ _publ_author_name 'Comodi P' 'Nazzareni S' 'Zanazzi P F' 'Speziale S' _journal_name_full 'American Mineralogist' _journal_volume 93 _journal_year 2008 _journal_page_first 1530 _journal_page_last 1537 _publ_section_title ; High-pressure behavior of gypsum: A single-crystal X-ray study Note: P = 0.0001 GPa ; _database_code_amcsd 0004651 _chemical_compound_source 'Valle di Caramanico, Abruzzo, Italy' _chemical_formula_sum 'Ca S O6 H4' _cell_length_a 6.277 _cell_length_b 15.181 _cell_length_c 5.672 _cell_angle_alpha 90 _cell_angle_beta 114.11 _cell_angle_gamma 90 _cell_volume 493.340 _exptl_crystal_density_diffrn 2.318 _symmetry_space_group_name_H-M 'C 1 2/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' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-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 Ca 0.00000 0.17050 0.25000 0.01170 S 0.00000 0.32727 0.75000 0.00990 O1 0.08319 0.27218 0.59103 0.01690 O2 0.19997 0.38195 0.91298 0.01690 OW -0.20823 0.06826 -0.07831 0.02410 H1 -0.25800 0.08700 -0.23400 0.03300 H2 -0.24400 0.02000 -0.07700 0.04400