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 = 400 K
;
_database_code_amcsd 0007458
_chemical_formula_sum 'Fe3 Ca Si2 O9 H'
_cell_length_a 13.0531
_cell_length_b 8.8344
_cell_length_c 5.8692
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 676.814
_exptl_crystal_density_diffrn      4.012
_symmetry_space_group_name_H-M 'P n a m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  '1/2-x,1/2+y,1/2+z'
  '1/2+x,1/2-y,1/2-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   0.89033   0.05069   0.00646   0.00930
FeB   0.94032   0.73939   0.25000   0.01010
Ca   0.81294   0.37062   0.75000   0.01020
Si1   0.95960   0.36816   0.25000   0.00650
Si2   0.67956   0.22704   0.25000   0.00670
O1   0.01034   0.02908   0.75000   0.01310
O2o   0.93618   0.27203   0.01676   0.00940
O3   0.77722   0.10929   0.25000   0.00940
O4o   0.67096   0.32975   0.01886   0.01040
O5   0.58469   0.10115   0.25000   0.00920
O6   0.60171   0.02444   0.75000   0.01330
O-H7   0.79764   0.10918   0.75000   0.00950
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 0.00930 0.00900 0.00970 -0.00020 -0.00080 0.00100
FeB 0.01110 0.00900 0.01040 -0.00070 0.00000 0.00000
Ca 0.00950 0.00850 0.01270 0.00090 0.00000 0.00000
Si1 0.00710 0.00680 0.00590 0.00000 0.00000 0.00000
Si2 0.00720 0.00690 0.00620 0.00080 0.00000 0.00000
O1 0.01390 0.01130 0.01430 0.00140 0.00000 0.00000
O2o 0.01200 0.00930 0.00710 -0.00230 -0.00070 -0.00190
O3 0.00760 0.00940 0.01130 0.00200 0.00000 0.00000
O4o 0.01180 0.00980 0.00980 0.00060 0.00070 0.00150
O5 0.00760 0.00840 0.01180 0.00050 0.00000 0.00000
O6 0.01220 0.00960 0.01830 -0.00270 0.00000 0.00000
O-H7 0.01050 0.00950 0.00880 0.00050 0.00000 0.00000