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 = 295 K
_database_code_amcsd 0007453
13.0387 8.8204 5.8640 90 90.266 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   .89019 .04983 .00727 .0072  .0067  .0064  .0086 -.0002 -.0003  .0006
FeAm   .89004 .05172 .49272 .0067  .0060  .0061  .0080 -.0002  .0003 -.0004
FeB    .94063 .73996 .24886 .0076  .0081  .0061  .0087 -.0007 -.0001 -.0003
Ca     .81296 .37035 .75267 .0077  .0066  .0060  .0107  .0006  .0000 -.0001
Si1    .95955 .36831 .24296 .0052  .0054  .0047  .0057  .0000  .0003  .0002
Si2    .67949 .22724 .25156 .0053  .0047  .0055  .0058  .0002  .0001  .0001
O1     .00986 .02900 .73935 .0102  .0079  .0095  .0134  .0017 -.0005 -.0002
O2o    .93712 .27206 .01614 .0076  .0090  .0069  .0072 -.0009 -.0003 -.0014
O2m    .93547 .27264 .48315 .0080  .0089  .0075  .0077 -.0011 -.0006  .0006
O3     .77717 .10951 .25521 .0072  .0057  .0064  .0097  .0017  .0003 -.0001
O4o    .67137 .32852 .01910 .0078  .0087  .0069  .0079  .0000  .0004  .0007
O4m    .67068 .33130 .48206 .0080  .0086  .0075  .0080  .0000  .0005 -.0020
O5     .58481 .10087 .25308 .0074  .0051  .0064  .0107  .0001  .0001 -.0017
O6     .60193 .02508 .75216 .0104  .0075  .0065  .0174 -.0022  .0004  .0008
OH7    .79767 .10973 .74510 .0077  .0069  .0082  .0081  .0011  .0009  .0001