data_global
_chemical_name_mineral 'Forsterite'
loop_
_publ_author_name
'Hazen R M'
_journal_name_full 'American Mineralogist'
_journal_volume 61 
_journal_year 1976
_journal_page_first 1280
_journal_page_last 1293
_publ_section_title
;
 Effects of temperature and pressure on the crystal structure of forsterite
 T = 23 C P = 20 kb
 olivine
;
_database_code_amcsd 0000550
_chemical_formula_sum 'Si Mg2 O4'
_cell_length_a 4.743
_cell_length_b 10.09
_cell_length_c 5.954
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 284.940
_exptl_crystal_density_diffrn      3.280
_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_U_iso_or_equiv
Si   0.42700   0.09500   0.25000   0.00469
Mg1   0.00000   0.00000   0.00000   0.00203
Mg2   0.99200   0.27700   0.25000   0.00469
O1   0.77100   0.09200   0.25000  -0.00127
O2   0.22700   0.44700   0.25000 ?
O3   0.27800   0.16200   0.03700   0.00253