data_global
_chemical_name_mineral 'Forsterite'
loop_
_publ_author_name
'Heuer M'
_journal_name_full 'Journal of Applied Crystallography'
_journal_volume 34 
_journal_year 2001
_journal_page_first 271
_journal_page_last 279
_publ_section_title
;
 The determination of site occupancies using a new strategy in Rietveld refinements
 Note: results of the conventional Rietveld refinement on the whole data set
;
_database_code_amcsd 0020681
_chemical_compound_source 'Synthetic'
_chemical_formula_sum '(Mg1.77 Fe.23) Si O4'
_cell_length_a 4.76450
_cell_length_b 10.23467
_cell_length_c 5.99727
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 292.445
_exptl_crystal_density_diffrn      3.360
_symmetry_space_group_name_H-M 'P b n 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_occupancy
_atom_site_U_iso_or_equiv
MgM1   0.00000   0.00000   0.00000   0.87700   0.01140
FeM1   0.00000   0.00000   0.00000   0.12300   0.01140
MgM2   0.98780   0.27730   0.25000   0.89300   0.01229
FeM2   0.98780   0.27730   0.25000   0.10700   0.01229
Si   0.42740   0.09440   0.25000   1.00000   0.00988
O1   0.76480   0.09010   0.25000   1.00000   0.00532
O2   0.22270   0.44980   0.25000   1.00000   0.00532
O3   0.28150   0.16100   0.03920   1.00000   0.00532