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 = 3.94 GPa ; _database_code_amcsd 0004658 _chemical_compound_source 'Valle di Caramanico, Abruzzo, Italy' _chemical_formula_sum 'Ca S O6 H4' _cell_length_a 6.136 _cell_length_b 14.912 _cell_length_c 5.556 _cell_angle_alpha 90 _cell_angle_beta 115.73 _cell_angle_gamma 90 _cell_volume 457.969 _exptl_crystal_density_diffrn 2.497 _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 0.16720 0.25000 0.00900 S 0.00000 0.32550 0.75000 0.00500 O1 0.08400 0.27200 0.58900 0.01100 O2 0.20800 0.38400 0.92500 0.01300 WatOW -0.22600 0.06300 -0.07800 0.01500