data_global
_chemical_name_mineral 'Ahrensite'
loop_
_publ_author_name
'Ma C'
'Tschauner O'
'Beckett J R'
'Liu Y'
'Rossman G R'
'Sinogeikin S V'
'Smith J S'
'Taylor L A'
_journal_name_full 'Geochimica et Cosmochimica Acta'
_journal_volume 184 
_journal_year 2016
_journal_page_first 240
_journal_page_last 256
_publ_section_title
;
 Ahrensite, gamma-Fe2SiO4, a new shock-metamorphic mineral from the Tissint meteorite:
 Implications for the Tissint shock event on Mars
;
_database_code_amcsd 0021229
_chemical_compound_source 'Tissint meteorite'
_chemical_formula_sum 'Fe1.15 Mg.86 Si1.04 O4'
_cell_length_a 8.1629
_cell_length_b 8.1629
_cell_length_c 8.1629
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 543.918
_exptl_crystal_density_diffrn      4.355
_symmetry_space_group_name_H-M 'F d 3 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2+y,1/2+z'
  '1/2+x,y,1/2+z'
  '1/2+x,1/2+y,z'
  '3/4+z,1/2-x,1/4+y'
  '3/4+z,-x,3/4+y'
  '1/4+z,1/2-x,3/4+y'
  '1/4+z,-x,1/4+y'
  '3/4-y,1/2+z,1/4-x'
  '3/4-y,+z,3/4-x'
  '1/4-y,1/2+z,3/4-x'
  '1/4-y,+z,1/4-x'
  '3/4+x,1/2-y,1/4+z'
  '3/4+x,-y,3/4+z'
  '1/4+x,1/2-y,3/4+z'
  '1/4+x,-y,1/4+z'
  '3/4-z,1/2+x,1/4-y'
  '3/4-z,+x,3/4-y'
  '1/4-z,1/2+x,3/4-y'
  '1/4-z,+x,1/4-y'
  '3/4+y,1/2-z,1/4+x'
  '3/4+y,-z,3/4+x'
  '1/4+y,1/2-z,3/4+x'
  '1/4+y,-z,1/4+x'
  '3/4-x,1/2+y,1/4-z'
  '3/4-x,+y,3/4-z'
  '1/4-x,1/2+y,3/4-z'
  '1/4-x,+y,1/4-z'
  '1/2+x,3/4-z,1/4-y'
  '1/2+x,1/4-z,3/4-y'
  '+x,3/4-z,3/4-y'
  '+x,1/4-z,1/4-y'
  '1/2-z,3/4+y,1/4+x'
  '1/2-z,1/4+y,3/4+x'
  '-z,3/4+y,3/4+x'
  '-z,1/4+y,1/4+x'
  '1/2+y,3/4-x,1/4-z'
  '1/2+y,1/4-x,3/4-z'
  '+y,3/4-x,3/4-z'
  '+y,1/4-x,1/4-z'
  '1/2-x,3/4+z,1/4+y'
  '1/2-x,1/4+z,3/4+y'
  '-x,3/4+z,3/4+y'
  '-x,1/4+z,1/4+y'
  '1/2+z,3/4-y,1/4-x'
  '1/2+z,1/4-y,3/4-x'
  '+z,3/4-y,3/4-x'
  '+z,1/4-y,1/4-x'
  '1/2-y,3/4+x,1/4+z'
  '1/2-y,1/4+x,3/4+z'
  '-y,3/4+x,3/4+z'
  '-y,1/4+x,1/4+z'
  'x,1/2+z,1/2+y'
  'x,+z,+y'
  '1/2+x,1/2+z,+y'
  '1/2+x,+z,1/2+y'
  '-z,1/2-y,1/2-x'
  '-z,-y,-x'
  '1/2-z,1/2-y,-x'
  '1/2-z,-y,1/2-x'
  'y,1/2+x,1/2+z'
  'y,+x,+z'
  '1/2+y,1/2+x,+z'
  '1/2+y,+x,1/2+z'
  '-x,1/2-z,1/2-y'
  '-x,-z,-y'
  '1/2-x,1/2-z,-y'
  '1/2-x,-z,1/2-y'
  'z,1/2+y,1/2+x'
  'z,+y,+x'
  '1/2+z,1/2+y,+x'
  '1/2+z,+y,1/2+x'
  '-y,1/2-x,1/2-z'
  '-y,-x,-z'
  '1/2-y,1/2-x,-z'
  '1/2-y,-x,1/2-z'
  '3/4+z,1/4+x,1/2-y'
  '3/4+z,3/4+x,-y'
  '1/4+z,1/4+x,-y'
  '1/4+z,3/4+x,1/2-y'
  '3/4-y,1/4-z,1/2+x'
  '3/4-y,3/4-z,+x'
  '1/4-y,1/4-z,+x'
  '1/4-y,3/4-z,1/2+x'
  '3/4+x,1/4+y,1/2-z'
  '3/4+x,3/4+y,-z'
  '1/4+x,1/4+y,-z'
  '1/4+x,3/4+y,1/2-z'
  '3/4-z,1/4-x,1/2+y'
  '3/4-z,3/4-x,+y'
  '1/4-z,1/4-x,+y'
  '1/4-z,3/4-x,1/2+y'
  '3/4+y,1/4+z,1/2-x'
  '3/4+y,3/4+z,-x'
  '1/4+y,1/4+z,-x'
  '1/4+y,3/4+z,1/2-x'
  '3/4-x,1/4-y,1/2+z'
  '3/4-x,3/4-y,+z'
  '1/4-x,1/4-y,+z'
  '1/4-x,3/4-y,1/2+z'
  '-z,3/4+x,3/4+y'
  '-z,1/4+x,1/4+y'
  '1/2-z,3/4+x,1/4+y'
  '1/2-z,1/4+x,3/4+y'
  'y,3/4-z,3/4-x'
  'y,1/4-z,1/4-x'
  '1/2+y,3/4-z,1/4-x'
  '1/2+y,1/4-z,3/4-x'
  '-x,3/4+y,3/4+z'
  '-x,1/4+y,1/4+z'
  '1/2-x,3/4+y,1/4+z'
  '1/2-x,1/4+y,3/4+z'
  'z,3/4-x,3/4-y'
  'z,1/4-x,1/4-y'
  '1/2+z,3/4-x,1/4-y'
  '1/2+z,1/4-x,3/4-y'
  '-y,3/4+z,3/4+x'
  '-y,1/4+z,1/4+x'
  '1/2-y,3/4+z,1/4+x'
  '1/2-y,1/4+z,3/4+x'
  'x,3/4-y,3/4-z'
  'x,1/4-y,1/4-z'
  '1/2+x,3/4-y,1/4-z'
  '1/2+x,1/4-y,3/4-z'
  '1/4-x,1/2+z,3/4-y'
  '1/4-x,+z,1/4-y'
  '3/4-x,1/2+z,1/4-y'
  '3/4-x,+z,3/4-y'
  '1/4+z,1/2-y,3/4+x'
  '1/4+z,-y,1/4+x'
  '3/4+z,1/2-y,1/4+x'
  '3/4+z,-y,3/4+x'
  '1/4-y,1/2+x,3/4-z'
  '1/4-y,+x,1/4-z'
  '3/4-y,1/2+x,1/4-z'
  '3/4-y,+x,3/4-z'
  '1/4+x,1/2-z,3/4+y'
  '1/4+x,-z,1/4+y'
  '3/4+x,1/2-z,1/4+y'
  '3/4+x,-z,3/4+y'
  '1/4-z,1/2+y,3/4-x'
  '1/4-z,+y,1/4-x'
  '3/4-z,1/2+y,1/4-x'
  '3/4-z,+y,3/4-x'
  '1/4+y,1/2-x,3/4+z'
  '1/4+y,-x,1/4+z'
  '3/4+y,1/2-x,1/4+z'
  '3/4+y,-x,3/4+z'
  '3/4-x,3/4-z,y'
  '3/4-x,1/4-z,1/2+y'
  '1/4-x,3/4-z,1/2+y'
  '1/4-x,1/4-z,y'
  '3/4+z,3/4+y,-x'
  '3/4+z,1/4+y,1/2-x'
  '1/4+z,3/4+y,1/2-x'
  '1/4+z,1/4+y,-x'
  '3/4-y,3/4-x,z'
  '3/4-y,1/4-x,1/2+z'
  '1/4-y,3/4-x,1/2+z'
  '1/4-y,1/4-x,z'
  '3/4+x,3/4+z,-y'
  '3/4+x,1/4+z,1/2-y'
  '1/4+x,3/4+z,1/2-y'
  '1/4+x,1/4+z,-y'
  '3/4-z,3/4-y,x'
  '3/4-z,1/4-y,1/2+x'
  '1/4-z,3/4-y,1/2+x'
  '1/4-z,1/4-y,x'
  '3/4+y,3/4+x,-z'
  '3/4+y,1/4+x,1/2-z'
  '1/4+y,3/4+x,1/2-z'
  '1/4+y,1/4+x,-z'
  '-z,-x,-y'
  '-z,1/2-x,1/2-y'
  '1/2-z,-x,1/2-y'
  '1/2-z,1/2-x,-y'
  'y,z,x'
  'y,1/2+z,1/2+x'
  '1/2+y,z,1/2+x'
  '1/2+y,1/2+z,x'
  '-x,-y,-z'
  '-x,1/2-y,1/2-z'
  '1/2-x,-y,1/2-z'
  '1/2-x,1/2-y,-z'
  'z,x,y'
  'z,1/2+x,1/2+y'
  '1/2+z,x,1/2+y'
  '1/2+z,1/2+x,y'
  '-y,-z,-x'
  '-y,1/2-z,1/2-x'
  '1/2-y,-z,1/2-x'
  '1/2-y,1/2-z,-x'
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
Fe   0.50000   0.50000   0.50000   0.56000   0.00697
Mg   0.50000   0.50000   0.50000   0.43000   0.00697
Si   0.50000   0.50000   0.50000   0.03000   0.00697
Si   0.12500   0.12500   0.12500   0.98000   0.00291
Fe   0.12500   0.12500   0.12500   0.03000   0.00291
O   0.74800   0.74800   0.74800   1.00000   0.00317