Pigeonite Clark J R, Ross M, Appleman D E American Mineralogist 56 (1971) 888-908 Crystal chemistry of a lunar pigeonite class b data refinement _database_code_amcsd 0000248 9.678 8.905 5.227 90 108.71 90 P2_1/c atom x y z occ Biso B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Mg1 .2506 .6548 .2300 .67 .55 Fe1 .2506 .6548 .2300 .33 .55 Mg2 .2564 .0167 .2246 .41 .51 .0017 .0018 .0038 .0003 .0006 .0004 Fe2 .2564 .0167 .2246 .59 .51 .0017 .0018 .0038 .0003 .0006 .0004 SiA .0434 .3399 .2844 .40 SiB .5520 .8364 .2368 .34 O1A .8684 .3373 .1740 .57 O1B .3755 .8357 .1296 .43 O2A .1231 .4977 .3312 .78 O2B .6314 .9850 .3814 .59 O3A .1048 .2683 .5917 1.12 .0022 .0054 .0095 .0000 .0016 .0033 O3B .6045 .7047 .4707 1.05 .0022 .0044 .0110 .0007 .0022 .0026