data_global
_chemical_name_mineral 'Ilvaite'
loop_
_publ_author_name
'Ghose S'
'Hewat A W'
'Marezio M'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 11 
_journal_year 1984
_journal_page_first 67
_journal_page_last 74
_publ_section_title
;
 A neutron powder diffraction study of the crystal and
 magnetic structures of ilvaite from 305 K to 5 K - a mixed
 valence iron silicate with an electronic transition
 Sample: T = 80 K
;
_database_code_amcsd 0007362
_chemical_formula_sum 'Ca (Fe2.825 Mn.175) Si2 O9 H'
_cell_length_a 13.0230
_cell_length_b 8.7994
_cell_length_c 5.8422
_cell_angle_alpha 90
_cell_angle_beta 90.231
_cell_angle_gamma 90
_cell_volume 669.479
_exptl_crystal_density_diffrn      4.054
_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_occupancy
_atom_site_U_iso_or_equiv
Ca   0.81280   0.36930   0.73640   1.00000   0.02115
FeM11   0.88880   0.05530   0.00880   0.97500   0.00608
MnM11   0.88880   0.05530   0.00880   0.02500   0.00608
FeM12   0.88890   0.04710   0.49200   0.95000   0.00608
MnM12   0.88890   0.04710   0.49200   0.05000   0.00608
FeM2   0.94130   0.74260   0.24370   0.90000   0.00659
MnM2   0.94130   0.74260   0.24370   0.10000   0.00659
Si1   0.96230   0.36620   0.22610   1.00000   0.01013
Si2   0.67840   0.23000   0.25400   1.00000   0.01013
O1   0.00980   0.02910   0.73190   1.00000   0.01279
O21   0.93800   0.27300   0.01390   1.00000   0.01279
O22   0.93430   0.27500   0.48630   1.00000   0.01279
O5   0.58530   0.10280   0.26060   1.00000   0.01279
O6   0.60060   0.02480   0.75250   1.00000   0.01279
O3   0.77810   0.10870   0.25860   1.00000   0.01279
O41   0.66760   0.33070   0.01670   1.00000   0.01279
O42   0.67260   0.33340   0.47700   1.00000   0.01279
O7   0.79560   0.10470   0.73800   1.00000   0.01279
H   0.73750   0.06050   0.74120   1.00000   0.02052