Cummingtonite Yang H, Smyth J R American Mineralogist 81 (1996) 363-368 Crystal structure of a P2_1/m ferromagnesian cummingtonite at 140 K T = 295 K _database_code_amcsd 0001789 9.502 18.126 5.309 90 102.07 90 C2/m atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Mg1 0 .0869 .5 .800 .0021 .0004 .0036 0 .0008 0 Fe1 0 .0869 .5 .200 .0021 .0004 .0036 0 .0008 0 Mg2 0 .1772 0 .911 .0017 .0004 .0048 0 .0004 0 Fe2 0 .1772 0 .089 .0017 .0004 .0048 0 .0004 0 Mg3 0 0 0 .831 .0020 .0004 .0046 0 .0001 0 Fe3 0 0 0 .169 .0020 .0004 .0046 0 .0001 0 Mg4 0 .2591 .5 .094 .0024 .0007 .0056 0 .0014 0 Fe4 0 .2591 .5 .906 .0024 .0007 .0056 0 .0014 0 Si1 .2877 .0841 .2744 .0014 .0003 .0036 -.0001 .0002 -.0001 Si2 .2977 .1689 .7811 .0012 .0003 .0034 -.0001 .0001 .0000 O1 .1138 .0871 .2094 .0013 .0005 .0045 .0000 .0004 -.0001 O2 .1240 .1724 .7194 .0016 .0005 .0057 .0000 .0003 .0004 O3 .1143 0 .7088 .0022 .0004 .0073 0 .0009 0 O4 .3803 .2453 .7696 .0030 .0006 .0076 -.0004 .0005 .0002 O5 .3517 .1312 .0645 .0019 .0009 .0065 -.0001 .0005 .0014 O6 .3500 .1184 .5588 .0022 .0013 .0077 .0003 -.0001 -.0012 O7 .3433 0 .2710 .0027 .0002 .0125 0 .0010 0