data_global _chemical_name_mineral 'Diopside' loop_ _publ_author_name 'Levien L' 'Prewitt C T' _journal_name_full 'American Mineralogist' _journal_volume 66 _journal_year 1981 _journal_page_first 315 _journal_page_last 323 _publ_section_title ; High-pressure structural study of diopside P = 23.6 kbar pyroxene ; _database_code_amcsd 0000812 _chemical_formula_sum 'Si2 Mg Ca O6' _cell_length_a 9.6809 _cell_length_b 8.847 _cell_length_c 5.2169 _cell_angle_alpha 90 _cell_angle_beta 105.57 _cell_angle_gamma 90 _cell_volume 430.415 _exptl_crystal_density_diffrn 3.342 _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 Si 0.28637 0.09410 0.22850 Mg1 0.00000 0.90920 0.25000 Ca2 0.00000 0.30260 0.25000 O1 0.11520 0.08640 0.14200 O2 0.36090 0.25150 0.31920 O3 0.35170 0.01850 0.99210 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Si 0.00458 0.00634 0.00486 -0.00017 0.00142 -0.00068 Mg1 0.00617 0.00317 0.00461 0.00000 0.00024 0.00000 Ca2 0.01040 0.00317 0.00678 0.00000 -0.00024 0.00000 O1 0.00617 0.00040 0.00768 0.00000 0.00024 0.00045 O2 0.01013 0.01071 0.00589 -0.00125 0.00166 -0.00068 O3 0.00705 0.00991 0.00512 -0.00084 0.00142 -0.00203