Ilvaite Ghose S, Tsukimura K, Hatch D M Physics and Chemistry of Minerals 16 (1989) 483-496 Phase transitions in ilvaite, a mixed-valence iron silicate II. A single-crystal X-ray diffraction study and Landau theory of the monoclinic to orthorhombic phase transition induced by charge delocalization Sample: T = 320 K _database_code_amcsd 0007454 13.0398 8.8217 5.8644 90 90.244 90 P2_1/a atom x y z Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) FeAo .89024 .05003 .00716 .0079 .0074 .0073 .0091 -.0001 -.0005 .0007 FeAm .89007 .05154 .49299 .0076 .0072 .0068 .0088 -.0001 .0003 -.0007 FeB .94058 .73980 .24900 .0085 .0089 .0070 .0096 -.0007 -.0001 -.0001 Ca .81289 .37050 .75215 .0086 .0076 .0068 .0114 .0005 -.0001 .0000 Si1 .95949 .36835 .24943 .0060 .0064 .0059 .0058 .0001 -.0001 -.0001 Si2 .67946 .22724 .25129 .0059 .0060 .0055 .0063 .0006 .0001 -.0001 O1 .00994 .02927 .74147 .0108 .0087 .0091 .0149 .0016 -.0010 .0002 O2o .93690 .27210 .01664 .0084 .0095 .0089 .0070 -.0020 -.0012 .0018 O2m .93553 .27220 .48305 .0080 .0096 .0071 .0074 -.0017 .0005 .0013 O3 .77724 .10954 .25435 .0094 .0082 .0068 .0104 .0016 -.0003 -.0006 O4o .67128 .32886 .01924 .0089 .0099 .0078 .0090 -.0005 -.0001 .0004 O4m .67086 .33099 .48207 .0090 .0114 .0070 .0086 .0021 -.0005 -.0016 O5 .58489 .10080 .25203 .0082 .0054 .0074 .0121 .0002 -.0004 -.0008 O6 .60183 .02472 .75188 .0112 .0098 .0073 .0166 -.0018 .0002 .0003 OH7 .79822 .10942 .74629 .0086 .0078 .0090 .0091 .0004 -.0004 .0008