Spinel Martignago F, Dal Negro A, Carbonin S Physics and Chemistry of Minerals 30 (2003) 401-408 How Cr3+ and Fe3+ affect Mg-Al order-disorder transformation at high temperature in natural spinels Sample: H-Cr, 3rd run, T = 900 C _database_code_amcsd 0008808 8.1726 8.1726 8.1726 90 90 90 *Fd3m .125 .125 .125 atom x y z occ Uiso AlT .125 .125 .125 .222 .0170 MgT .125 .125 .125 .778 .0170 AlM .5 .5 .5 .806 .0154 MgM .5 .5 .5 .1085 .0154 CrM .5 .5 .5 .081 .0154 MnM .5 .5 .5 .001 .0154 ZnM .5 .5 .5 .0035 .0154 O .26197 .26197 .26197 .0187