data_global
_chemical_name_mineral 'Kosmochlor'
loop_
_publ_author_name
'Origlieri M J'
'Downs R T'
'Thompson R M'
'Pommier C J S'
'Denton M B'
'Harlow G E'
_journal_name_full 'American Mineralogist'
_journal_volume 88 
_journal_year 2003
_journal_page_first 1025
_journal_page_last 1032
_publ_section_title
;
 High-pressure crystal structure of kosmochlor, NaCrSi2O6, and systematics of
 anisotropic compression in pyroxenes
 Sample: P = 6.25 GPa
;
_database_code_amcsd 0003139
_chemical_formula_sum 'Na Cr Si2 O6'
_cell_length_a 9.4295
_cell_length_b 8.5700
_cell_length_c 5.1844
_cell_angle_alpha 90
_cell_angle_beta 106.999
_cell_angle_gamma 90
_cell_volume 400.651
_exptl_crystal_density_diffrn      3.766
_symmetry_space_group_name_H-M 'C 1 2/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Na2   0.00000   0.30340   0.25000   0.01646
Cr1   0.00000   0.90870   0.25000   0.01013
Si   0.29290   0.09350   0.23430   0.01089
O1   0.11500   0.08050   0.13800   0.01013
O2   0.36200   0.26220   0.31300   0.01393
O3   0.35400   0.01500   0.00200   0.01140