data_global
_chemical_name_mineral 'Ilvaite'
loop_
_publ_author_name
'Ghose S'
'Tsukimura K'
'Hatch D M'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 16 
_journal_year 1989
_journal_page_first 483
_journal_page_last 496
_publ_section_title
;
 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
_chemical_formula_sum 'Fe3 Ca Si2 O9 H'
_cell_length_a 13.0497
_cell_length_b 8.8291
_cell_length_c 5.8652
_cell_angle_alpha 90
_cell_angle_beta 90.029
_cell_angle_gamma 90
_cell_volume 675.771
_exptl_crystal_density_diffrn      4.018
_symmetry_space_group_name_H-M 'P 1 21/a 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
FeAo   0.89027   0.05067   0.00689   0.00950
FeAm   0.89017   0.05094   0.49302   0.00920
FeB   0.94047   0.73949   0.24974   0.01020
Ca   0.81298   0.37052   0.75032   0.01020
Si1   0.95956   0.36835   0.24987   0.00690
Si2   0.67949   0.22708   0.25028   0.00720
O1   0.00982   0.02881   0.74902   0.01370
O2o   0.93645   0.27245   0.01641   0.00930
O2m   0.93615   0.27195   0.48393   0.00900
O3   0.77704   0.10967   0.25046   0.00960
O4o   0.67093   0.32970   0.01853   0.00960
O4m   0.67097   0.32959   0.48165   0.01040
O5   0.58527   0.10120   0.25028   0.00940
O6   0.60194   0.02447   0.74977   0.01280
O-H7   0.79794   0.10926   0.74962   0.00970
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
FeAo 0.01090 0.00870 0.00900 -0.00010 -0.00080 0.00090
FeAm 0.01070 0.00850 0.00860 -0.00030 0.00040 -0.00050
FeB 0.01280 0.00870 0.00930 -0.00070 -0.00030 -0.00020
Ca 0.01120 0.00820 0.01140 0.00100 -0.00060 0.00000
Si1 0.00890 0.00680 0.00520 0.00000 -0.00020 -0.00040
Si2 0.00920 0.00710 0.00550 0.00030 -0.00040 0.00030
O1 0.01460 0.01160 0.01490 0.00040 0.00000 -0.00030
O2o 0.01240 0.01020 0.00530 -0.00130 0.00060 -0.00140
O2m 0.01210 0.01020 0.00490 -0.00050 -0.00080 0.00150
O3 0.01020 0.00920 0.00970 0.00190 -0.00050 -0.00060
O4o 0.01170 0.00910 0.00820 0.00030 0.00000 0.00130
O4m 0.01270 0.01100 0.00760 0.00080 -0.00010 -0.00260
O5 0.01050 0.00710 0.01090 0.00170 0.00040 -0.00060
O6 0.01290 0.01020 0.01540 -0.00280 -0.00030 -0.00040
O-H7 0.01130 0.00900 0.00900 0.00140 0.00070 0.00100