data_global
_chemical_name_mineral 'Enstatite'
loop_
_publ_author_name
'Yang H'
'Ghose S'
_journal_name_full 'American Mineralogist'
_journal_volume 80 
_journal_year 1995
_journal_page_first 9
_journal_page_last 20
_publ_section_title
;
 A transitional structural state and anomalous Fe-Mg order-disorder in Mg-rich
 orthopyroxene, (Mg0.75Fe0.25)2Si2O6
 T = 1200 K
;
_database_code_amcsd 0001696
_chemical_formula_sum '(Mg.751 Fe.249) Si O3'
_cell_length_a 18.4317
_cell_length_b 8.9822
_cell_length_c 5.2647
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 871.609
_exptl_crystal_density_diffrn      3.299
_symmetry_space_group_name_H-M 'P b c a'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '1/2+x,y,1/2-z'
  '1/2-x,-y,1/2+z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mg1   0.37500   0.65110   0.88840   0.88500
Fe1   0.37500   0.65110   0.88840   0.11500
Mg2   0.37630   0.48630   0.38530   0.61700
Fe2   0.37630   0.48630   0.38530   0.38300
SiA   0.27210   0.33960   0.06560   1.00000
SiB   0.47560   0.33800   0.78070   1.00000
O1A   0.18500   0.33920   0.05940   1.00000
O1B   0.56310   0.34240   0.78290   1.00000
O2A   0.31150   0.49650   0.07260   1.00000
O2B   0.43470   0.48700   0.70520   1.00000
O3A   0.30220   0.23390  -0.16580   1.00000
O3B   0.44900   0.21360   0.56640   1.00000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Mg1 0.02754 0.02698 0.02148 0.00000 -0.00295 0.00048
Fe1 0.02754 0.02698 0.02148 0.00000 -0.00295 0.00048
Mg2 0.04131 0.03597 0.03117 -0.00419 -0.01032 0.00192
Fe2 0.04131 0.03597 0.03117 -0.00419 -0.01032 0.00192
SiA 0.01721 0.02003 0.01643 -0.00168 0.00000 -0.00096
SiB 0.01721 0.02003 0.01910 0.00084 -0.00197 0.00000
O1A 0.01549 0.03188 0.02303 0.00000 0.00147 0.00000
O1B 0.02065 0.02861 0.02626 -0.00419 -0.00197 -0.00072
O2A 0.03614 0.02657 0.03061 -0.01258 -0.00492 0.00240
O2B 0.03442 0.02820 0.03145 0.01174 -0.00147 0.00479
O3A 0.02926 0.04782 0.01980 0.00335 -0.00197 -0.01413
O3B 0.02237 0.04782 0.03496 -0.00503 0.00197 -0.01797