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 = 53.0 kbar pyroxene ; _database_code_amcsd 0000815 _chemical_formula_sum 'Si2 Mg Ca O6' _cell_length_a 9.612 _cell_length_b 8.765 _cell_length_c 5.1793 _cell_angle_alpha 90 _cell_angle_beta 105.32 _cell_angle_gamma 90 _cell_volume 420.846 _exptl_crystal_density_diffrn 3.418 _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 0.28640 0.09460 0.22790 Mg1 0.00000 0.90970 0.25000 Ca2 0.00000 0.30400 0.25000 O1 0.11470 0.08800 0.14140 O2 0.36080 0.25420 0.32120 O3 0.35270 0.02130 0.98890 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 0.00348 0.00506 0.00392 -0.00045 0.00094 -0.00067 Mg1 0.00479 0.00545 0.00354 0.00000 0.00070 0.00000 Ca2 0.00914 0.00623 0.00518 0.00000 0.00000 0.00000 O1 0.00610 0.00701 0.00581 0.00041 0.00188 -0.00111 O2 0.00653 0.00739 0.00632 -0.00123 0.00094 -0.00067 O3 0.00697 0.00778 0.00493 -0.00041 0.00141 -0.00111