Diopside Raudsepp M, Hawthorne F C, Turnock A C American Mineralogist 75 (1990) 1274-1281 Crystal chemistry of synthetic pyroxenes on the join CaNiSi2O6-CaMgSi2O6 (diopside): A Rietveld refinement study sample Ni100, CaNiSi2O6 _database_code_amcsd 0001333 9.7359 8.8932 5.2284 90 105.830 90 C2/c atom x y z Biso Ni1 0 .9087 .25 0.37 Ca2 0 .2983 .25 .635 Si .2866 .0924 .2252 .349 O1 .1157 .0849 .1403 0.51 O2 .3578 .2540 .3230 0.65 O3 .3503 .0203 .9921 0.56