data_9001220
_chemical_name 'Enstatite'
loop_
_publ_author_name
'Angel R J'
'Gasparik T'
'Finger L W'
_journal_name_full "American Mineralogist"
_journal_volume 74
_journal_year 1989
_journal_page_first 599
_journal_page_last 603
_publ_section_title
;
 Crystal structure of a Cr-bearing pyroxene
 Sample: Mg1.4Cr.6Si2O6
;
_chemical_formula_sum 'Mg.712 Cr.306 Si.982 O3'
_cell_length_a 9.713
_cell_length_b 8.910
_cell_length_c 5.238
_cell_angle_alpha 90
_cell_angle_beta 109.41
_cell_angle_gamma 90
_cell_volume 427.547
_symmetry_space_group_name_H-M 'P 1 21/c 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+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   0.25060   0.65370   0.22530   0.94600
Cr1   0.25060   0.65370   0.22530   0.05400
Mg2   0.25280   0.01620   0.22090   0.47900
Cr2   0.25280   0.01620   0.22090   0.52100
SiA   0.04560   0.33870   0.28910   0.98300
CrA   0.04560   0.33870   0.28910   0.01700
SiB   0.54930   0.83810   0.24370   0.98100
CrB   0.54930   0.83810   0.24370   0.01900
O1A   0.86940   0.33470   0.17480   1.00000
O2A   0.12260   0.49840   0.32690   1.00000
O3A   0.10920   0.27530   0.60550   1.00000
O1B   0.37260   0.83990   0.13360   1.00000
O2B   0.63210   0.98710   0.38200   1.00000
O3B   0.60210   0.70660   0.48340   1.00000