data_global _chemical_name_mineral 'Diopside' loop_ _publ_author_name 'Thompson R M' 'Downs R T' _journal_name_full 'American Mineralogist' _journal_volume 93 _journal_year 2008 _journal_page_first 177 _journal_page_last 186 _publ_section_title ; The crystal structure of diopside at pressure to 10 GPa Sample: P = 1 atm ; _database_code_amcsd 0004495 _chemical_compound_source 'DeKalb, New York' _chemical_formula_sum 'Mg Ca Si2 O6' _cell_length_a 9.7397 _cell_length_b 8.9174 _cell_length_c 5.2503 _cell_angle_alpha 90 _cell_angle_beta 105.866 _cell_angle_gamma 90 _cell_volume 438.631 _exptl_crystal_density_diffrn 3.279 _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 Mg 0.00000 0.90808 0.25000 0.00393 Ca 0.00000 0.30148 0.25000 0.00823 Si 0.28619 0.09319 0.22936 0.00431 O1 0.11554 0.08690 0.14186 0.00697 O2 0.36094 0.25019 0.31776 0.00785 O3 0.35073 0.01744 0.99543 0.00709