Enstatite Yang H, Ghose S American Mineralogist 80 (1995) 9-20 A transitional structural state and anomalous Fe-Mg order-disorder in Mg-rich orthopyroxene, (Mg0.75Fe0.25)2Si2O6 T = 296 K _database_code_amcsd 0001693 18.2747 8.8729 5.1988 90 90 90 Pbca atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Mg1 .3757 .6543 .8702 .907 .0004 .0014 .0041 .0000 -.0001 .0000 Fe1 .3757 .6543 .8702 .093 .0004 .0014 .0041 .0000 -.0001 .0000 Mg2 .3776 .4848 .3640 .595 .0005 .0019 .0051 -.0001 -.0004 .0001 Fe2 .3776 .4848 .3640 .405 .0005 .0019 .0051 -.0001 -.0004 .0001 SiA .2717 .3408 .0521 .0003 .0014 .0040 .0000 .0000 .0000 SiB .4737 .3366 .7959 .0003 .0013 .0041 .0000 -.0001 .0000 O1A .1836 .3383 .0401 .0003 .0018 .0061 -.0001 .0003 -.0001 O1B .5626 .3387 .7968 .0003 .0018 .0059 .0000 .0000 .0001 O2A .3112 .5008 .0496 .0005 .0019 .0068 -.0002 -.0003 .0004 O2B .4334 .4841 .6927 .0005 .0017 .0067 .0002 -.0002 .0000 O3A .3027 .2267 -.1703 .0005 .0029 .0052 .0000 .0000 -.0011 O3B .4476 .1984 .5982 .0005 .0019 .0044 -.0001 -.0002 -.0003