Forsterite Baur W H American Mineralogist 57 (1972) 709-731 Computer-simulated crystal structures of observed and hypothetical Mg2SiO4 polymorphs of low and high density Locality: hypothetical _database_code_amcsd 0000276 4.79 10.19 5.85 90 90 90 Pbnm atom x y z Si .0945 .4078 .25 Mg1 0 0 0 Mg2 .0056 .2632 .75 O1 .2499 .0907 .75 O2 .2832 .0578 .25 O3 .2312 .3370 .4707