Forsterite
Birle J D, Gibbs G V, Moore P B, Smith J V
American Mineralogist 53 (1968) 807-824
Crystal structures of natural olivines
_database_code_amcsd 0000171
4.762 10.225 5.994 90 90 90 Pbnm
atom      x      y      z occ Biso
Mg1       0      0      0  .9  .33
Fe1       0      0      0  .1  .33
Mg2  .98975 .27743    .25  .9  .36
Fe2  .98975 .27743    .25  .1  .36
Si   .42693 .09434    .25      .20
O1   .76580 .09186    .25      .35
O2   .22012 .44779    .25      .42
O3   .27810 .16346 .03431      .41