Forsterite Ottonello G, Della Giusta A, Molin G M American Mineralogist 74 (1989) 411-421 Cation ordering in Ni-Mg olivines sample Ni.30B, synthesized at 902 C, then quenched Mg1.4Ni.6SiO4 _database_code_amcsd 0001216 4.7458 10.1986 5.9563 90 90 90 Pbnm atom x y z occ Biso Mg1 0 0 0 .468 0.57 Ni1 0 0 0 .532 0.57 Mg2 .9900 .2761 .25 .932 0.62 Ni2 .9900 .2761 .25 .068 0.62 Si .4257 .0936 .25 0.51 O1 .7660 .0924 .25 0.59 O2 .2202 .4461 .25 0.58 O3 .2763 .1626 .0326 0.62