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 Ni0, CaMgSi2O6 _database_code_amcsd 0001337 9.7470 8.9235 5.2524 90 105.939 90 C2/c atom x y z Biso Mg1 0 .9071 .25 0.37 Ca2 0 .2995 .25 .635 Si .2857 .0943 .2312 .349 O1 .1144 .0900 .1420 0.51 O2 .3619 .2516 .3176 0.65 O3 .3499 .0185 .9974 0.56