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 = 0.0001 GPa
 Note: altered y-coordinate of O2
;
_database_code_amcsd 0003133
_chemical_formula_sum 'Na Cr Si2 O6'
_cell_length_a 9.5720
_cell_length_b 8.7094
_cell_length_c 5.2678
_cell_angle_alpha 90
_cell_angle_beta 107.498
_cell_angle_gamma 90
_cell_volume 418.836
_exptl_crystal_density_diffrn      3.602
_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   0.29990   0.25000   0.01963
Cr1   0.00000   0.90769   0.25000   0.01153
Si   0.29259   0.09180   0.23430   0.01165
O1   0.11370   0.07840   0.13660   0.01279
O2   0.36050   0.25890   0.30330   0.01583
O3   0.35290   0.00950   0.00920   0.01444
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
Na2 0.02153 0.01729 0.01560 0.00000 -0.00116 0.00000
Cr1 0.01170 0.01153 0.00997 0.00000 0.00116 0.00000
Si 0.01182 0.01191 0.01036 0.00000 0.00186 0.00000
O1 0.01140 0.01460 0.01036 -0.00081 0.00093 0.00089
O2 0.01604 0.01499 0.01573 -0.00201 0.00325 -0.00022
O3 0.01478 0.01537 0.01240 0.00242 0.00325 -0.00044