data_global _chemical_name_mineral 'Diopside' loop_ _publ_author_name 'Raudsepp M' 'Hawthorne F C' 'Turnock A C' _journal_name_full 'American Mineralogist' _journal_volume 75 _journal_year 1990 _journal_page_first 1274 _journal_page_last 1281 _publ_section_title ; Crystal chemistry of synthetic pyroxenes on the join CaNiSi2O6-CaMgSi2O6 (diopside): A Rietveld refinement study sample Ni25, CaNi.22Mg.78Si2O6 ; _database_code_amcsd 0001336 _chemical_formula_sum '(Ni.22 Mg.78) Ca Si2 O6' _cell_length_a 9.7393 _cell_length_b 8.9095 _cell_length_c 5.2418 _cell_angle_alpha 90 _cell_angle_beta 105.850 _cell_angle_gamma 90 _cell_volume 437.550 _exptl_crystal_density_diffrn 3.402 _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 Ni1 0.00000 0.90720 0.25000 0.22000 0.00469 Mg1 0.00000 0.90720 0.25000 0.78000 0.00469 Ca2 0.00000 0.30000 0.25000 1.00000 0.00804 Si 0.28760 0.09050 0.22990 1.00000 0.00442 O1 0.11580 0.08610 0.14070 1.00000 0.00646 O2 0.36330 0.24880 0.32180 1.00000 0.00823 O3 0.34900 0.01800 0.99280 1.00000 0.00709