data_1011238
_chemical_name_systematic          'Magnesium iron(II) silicate *'
_chemical_name_mineral             'Hypersthene'
_chemical_compound_source          'from Mt. Dore, Auvergne, France'
_chemical_formula_structural       'Fe.3 Mg.7 Si O3'
_chemical_formula_sum              'Fe.3 Mg.7 O3 Si'
_publ_section_title                'The Structure of Enstatite, Mg Si O3'
loop_
_publ_author_name
  'Warren, B E'
  'Modell, D I'
_journal_name_full
;
Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik,
Kristallchemie (-144,1977)
;
_journal_coden_ASTM                ZEKGAX
_journal_volume                    75
_journal_year                      1930
_journal_page_first                1
_journal_page_last                 14
_cell_length_a                     18.2
_cell_length_b                     8.86
_cell_length_c                     5.2
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       838.5
_cell_formula_units_Z              16
_exptl_crystal_density_meas        3.39
_symmetry_space_group_name_H-M     'P b c a'
_symmetry_Int_Tables_number        61
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2-y,-z'
  '-x,1/2+y,1/2-z'
  '1/2-x,-y,1/2+z'
  '-x,-y,-z'
  '1/2-x,1/2+y,z'
  'x,1/2-y,1/2+z'
  '1/2+x,y,1/2-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Mg2+   2.000
  Fe2+   2.000
  Si4+   4.000
  O2-   -2.000
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_calc_flag
  Mg1   Mg2+   8 c 0.13 0.33 0.37 0.7  0 d
  Mg2   Mg2+   8 c 0.13 -0.04 0.37 0.7  0 d
  Fe1   Fe2+   8 c 0.13 0.33 0.37 0.3  0 d
  Fe2   Fe2+   8 c 0.13 -0.04 0.37 0.3  0 d
  Si1   Si4+   8 c 0.03 -0.35 0.29 1.  0 d
  Si2   Si4+   8 c 0.22 -0.15 0.04 1.  0 d
  O1    O2-    8 c 0.06 0.14 0.2 1.  0 d
  O2    O2-    8 c 0.06 0.5 0.2 1.  0 d
  O3    O2-    8 c 0.05 -0.25 0.05 1.  0 d
  O4    O2-    8 c 0.19 0.35 0.06 1.  0 d
  O5    O2-    8 c 0.19 0.01 0.05 1.  0 d
  O6    O2-    8 c 0.2 -0.25 0.3 1.  0 d