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 = 360 K _database_code_amcsd 0007456 13.0497 8.8291 5.8652 90 90.029 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 .89027 .05067 .00689 .0095 .0109 .0087 .0090 -.0001 -.0008 .0009 FeAm .89017 .05094 .49302 .0092 .0107 .0085 .0086 -.0003 .0004 -.0005 FeB .94047 .73949 .24974 .0102 .0128 .0087 .0093 -.0007 -.0003 -.0002 Ca .81298 .37052 .75032 .0102 .0112 .0082 .0114 .0010 -.0006 .0000 Si1 .95956 .36835 .24987 .0069 .0089 .0068 .0052 .0000 -.0002 -.0004 Si2 .67949 .22708 .25028 .0072 .0092 .0071 .0055 .0003 -.0004 .0003 O1 .00982 .02881 .74902 .0137 .0146 .0116 .0149 .0004 .0000 -.0003 O2o .93645 .27245 .01641 .0093 .0124 .0102 .0053 -.0013 .0006 -.0014 O2m .93615 .27195 .48393 .0090 .0121 .0102 .0049 -.0005 -.0008 .0015 O3 .77704 .10967 .25046 .0096 .0102 .0092 .0097 .0019 -.0005 -.0006 O4o .67093 .32970 .01853 .0096 .0117 .0091 .0082 .0003 .0000 .0013 O4m .67097 .32959 .48165 .0104 .0127 .0110 .0076 .0008 -.0001 -.0026 O5 .58527 .10120 .25028 .0094 .0105 .0071 .0109 .0017 .0004 -.0006 O6 .60194 .02447 .74977 .0128 .0129 .0102 .0154 -.0028 -.0003 -.0004 OH7 .79794 .10926 .74962 .0097 .0113 .0090 .0090 .0014 .0007 .0010