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 = 380 K _database_code_amcsd 0007457 13.05330 8.83450 5.86740 90 90 90 Pnam 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 .05075 .00665 .0089 .0087 .0087 .0094 -.0001 -.0007 .0008 FeB .94035 .73943 .25 .0095 .0106 .0086 .0095 -.0006 0 0 Ca .81299 .37056 .75 .0097 .0089 .0082 .0121 .0007 0 0 Si1 .95958 .36809 .25 .0063 .0068 .0067 .0055 .0001 0 0 Si2 .67942 .22704 .25 .0063 .0067 .0068 .0057 .0006 0 0 O1 .01020 .02930 .75 .0131 .0137 .0112 .0144 .0003 0 0 O2o .93631 .27187 .01664 .0091 .0104 .0098 .0072 -.0013 -.0001 -.0017 O3 .77705 .10968 .25 .0094 .0097 .0088 .0097 .0011 0 0 O4o .67107 .32947 .01850 .0098 .0107 .0108 .0080 .0001 .0004 .0016 O5 .58481 .10132 .25 .0089 .0083 .0091 .0095 .0005 0 0 O6 .60190 .02427 .75 .0127 .0116 .0089 .0177 -.0029 0 0 OH7 .79761 .10879 .75 .0088 .0090 .0094 .0081 .0015 0 0