data_global _chemical_name_mineral 'Diopside' loop_ _publ_author_name 'Oberti R' 'Caporuscio F A' _journal_name_full 'American Mineralogist' _journal_volume 76 _journal_year 1991 _journal_page_first 1141 _journal_page_last 1152 _publ_section_title ; Crystal chemistry of clinopyroxenes from mantle eclogites: A study of the key role of the M2 site population by means of crystal-structure refinement sample SBB 3H, Di64Jd26, diopside - jadeite join ; _database_code_amcsd 0001366 _chemical_formula_sum 'Mg.65 Al.28 Fe.13 Ti.01 Ca.65 Na.26 Si2 O6' _cell_length_a 9.654 _cell_length_b 8.831 _cell_length_c 5.255 _cell_angle_alpha 90 _cell_angle_beta 106.52 _cell_angle_gamma 90 _cell_volume 429.519 _exptl_crystal_density_diffrn 3.329 _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_occupancy _atom_site_U_iso_or_equiv Mg1 0.00000 0.90590 0.25000 0.62000 0.00747 Al1 0.00000 0.90590 0.25000 0.28000 0.00747 Fe1 0.00000 0.90590 0.25000 0.09000 0.00747 Ti1 0.00000 0.90590 0.25000 0.01000 0.00747 Ca2 0.00000 0.30050 0.25000 0.65000 0.01127 Na2 0.00000 0.30050 0.25000 0.26000 0.01127 Mg2 0.00000 0.30050 0.25000 0.03000 0.00950 Fe2 0.00000 0.30050 0.25000 0.04000 0.00950 Si 0.28760 0.09280 0.22980 1.00000 0.00595 O1 0.11390 0.08350 0.13810 1.00000 0.01077 O2 0.36080 0.25350 0.31340 1.00000 0.01165 O3 0.35150 0.01540 -0.00090 1.00000 0.00887