data_Forsterit
_chemical_name_systematic          'Magnesium Silicate'
_chemical_formula_structural       'Mg2 Si O4'
_chemical_formula_sum              'Mg2 O4 Si1'
_chemical_name_mineral             Forsterite
_cell_length_a                     4.756(1)
_cell_length_b                     10.207(1)
_cell_length_c                     5.980(1)
_cell_angle_alpha                  90.
_cell_angle_beta                   90.
_cell_angle_gamma                  90.
_cell_volume                       290.3
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'P b n m'
_symmetry_Int_Tables_number        62
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
  1	'-x+1/2, y+1/2, z'
  2	'x, y, -z+1/2'
  3	'x+1/2, -y+1/2, z+1/2'
  4	'-x, -y, -z'
  5	'x+1/2, -y+1/2, -z'
  6	'-x, -y, z+1/2'
  7	'-x+1/2, y+1/2, -z+1/2'
  8	'x, y, z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
Mg2+	2
O2-	-2
Si4+	4
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_B_iso_or_equiv
Mg1 Mg2+ 4 a 0 0 0 1. 0 0.26(1) 
Mg2 Mg2+ 4 c 0.9915(2) 0.2774(1) 0.25 1. 0 0.22(1) 
Si1 Si4+ 4 c 0.4262(1) 0.0940(1) 0.25 1. 0 0.08(1) 
O1 O2- 4 c 0.7657(3) 0.0913(2) 0.25 1. 0 0.27(2) 
O2 O2- 4 c 0.2215(4) 0.4474(2) 0.25 1. 0 0.24(2) 
O3 O2- 8 d 0.2777(2) 0.1628(1) 0.0331(2) 1. 0 0.27(2) 

