data_global
_chemical_name 'Forsterite'
loop_
_publ_author_name
'Smyth J R'
'Hazen R M'
_journal_name_full "American Mineralogist"
_journal_volume 58 
_journal_year 1973
_journal_page_first 588
_journal_page_last 593
_publ_section_title
;
 The crystal structures of forsterite and hortonolite at several temperatures
 up to 900 C
 T = 300 C
;
_chemical_formula_sum 'Mg2 Si O4'
_cell_length_a 4.763
_cell_length_b 10.240
_cell_length_c 5.999
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 292.590
_symmetry_space_group_name_H-M 'P b n m'
loop_
_symmetry_equiv_pos_as_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_Uiso_or_equiv
Mg1   0.00000   0.00000   0.00000   0.00760
Mg2   0.99150   0.27800   0.25000   0.00722
Si   0.42570   0.09390   0.25000   0.00317
O1   0.76570   0.09100   0.25000   0.00798
O2   0.21770   0.44920   0.25000   0.00659
O3   0.28060   0.16190   0.03470   0.00747
