data_global
_chemical_name_mineral 'Enstatite'
loop_
_publ_author_name
'Hugh-Jones D A'
'Chopelas A'
'Angel R J'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 24 
_journal_year 1997
_journal_page_first 301
_journal_page_last 310
_publ_section_title
;
 Tetrahedral compression in (Mg,Fe)SiO3 orthopyroxenes
 Sample: P = 3.00 GPa, natural orthopyroxene
;
_database_code_amcsd 0008021
_chemical_formula_sum 'Mg1.66 Fe.24 Ca.012 Al.14 Si1.94 O6'
_cell_length_a 18.115
_cell_length_b 8.7184
_cell_length_c 5.1472
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 812.917
_exptl_crystal_density_diffrn      3.407
_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
_atom_site_U_iso_or_equiv
MgM1   0.37400   0.65410   0.86100   1.00000   0.00291
MgM2   0.37830   0.48210   0.35230   0.66000   0.00291
FeM2   0.37830   0.48210   0.35230   0.24000   0.00291
CaM2   0.37830   0.48210   0.35230   0.01200   0.00291
AlM2   0.37830   0.48210   0.35230   0.08000   0.00291
SiTA   0.26900   0.34330   0.04350   0.97000   0.00114
AlTA   0.26900   0.34330   0.04350   0.03000   0.00114
SiTB   0.47500   0.33790   0.80310   0.97000   0.00114
AlTB   0.47500   0.33790   0.80310   0.03000   0.00114
O1a   0.17700   0.33900   0.02900   1.00000   0.00317
O2a   0.31100   0.50600   0.03600   1.00000   0.00317
O3a   0.30300   0.22800   0.82100   1.00000   0.00317
O1b   0.56700   0.34100   0.80900   1.00000   0.00317
O2b   0.43200   0.48800   0.69100   1.00000   0.00317
O3b   0.45100   0.19100   0.61100   1.00000   0.00317