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 = 380 K
;
_database_code_amcsd 0007457
_chemical_formula_sum 'Fe3 Ca Si2 O9 H'
_cell_length_a 13.05330
_cell_length_b 8.83450
_cell_length_c 5.86740
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 676.625
_exptl_crystal_density_diffrn      4.013
_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   0.89027   0.05075   0.00665   0.00890
FeB   0.94035   0.73943   0.25000   0.00950
Ca   0.81299   0.37056   0.75000   0.00970
Si1   0.95958   0.36809   0.25000   0.00630
Si2   0.67942   0.22704   0.25000   0.00630
O1   0.01020   0.02930   0.75000   0.01310
O2o   0.93631   0.27187   0.01664   0.00910
O3   0.77705   0.10968   0.25000   0.00940
O4o   0.67107   0.32947   0.01850   0.00980
O5   0.58481   0.10132   0.25000   0.00890
O6   0.60190   0.02427   0.75000   0.01270
O-H7   0.79761   0.10879   0.75000   0.00880
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 0.00870 0.00870 0.00940 -0.00010 -0.00070 0.00080
FeB 0.01060 0.00860 0.00950 -0.00060 0.00000 0.00000
Ca 0.00890 0.00820 0.01210 0.00070 0.00000 0.00000
Si1 0.00680 0.00670 0.00550 0.00010 0.00000 0.00000
Si2 0.00670 0.00680 0.00570 0.00060 0.00000 0.00000
O1 0.01370 0.01120 0.01440 0.00030 0.00000 0.00000
O2o 0.01040 0.00980 0.00720 -0.00130 -0.00010 -0.00170
O3 0.00970 0.00880 0.00970 0.00110 0.00000 0.00000
O4o 0.01070 0.01080 0.00800 0.00010 0.00040 0.00160
O5 0.00830 0.00910 0.00950 0.00050 0.00000 0.00000
O6 0.01160 0.00890 0.01770 -0.00290 0.00000 0.00000
O-H7 0.00900 0.00940 0.00810 0.00150 0.00000 0.00000