data_global
_chemical_name_mineral 'Diopside'
loop_
_publ_author_name
'Oberti R'
'Caporuscio F A'
_journal_name_full 'American Mineralogist'
_journal_volume 76 
_journal_year 1991
_journal_page_first 1141
_journal_page_last 1152
_publ_section_title
;
 Crystal chemistry of clinopyroxenes from mantle eclogites: A study of the key
 role of the M2 site population by means of crystal-structure refinement
 sample SBB 7P, Di78Jd18, diopside - jadeite join
;
_database_code_amcsd 0001363
_chemical_formula_sum 'Mg.83 Cr.09 Al.1 Fe.05 Ca.78 Na.18 Si1.97 O6'
_cell_length_a 9.693
_cell_length_b 8.889
_cell_length_c 5.253
_cell_angle_alpha 90
_cell_angle_beta 106.34
_cell_angle_gamma 90
_cell_volume 434.323
_exptl_crystal_density_diffrn      3.320
_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_occupancy
_atom_site_U_iso_or_equiv
Mg1   0.00000   0.90680   0.25000   0.79000   0.00583
Cr1   0.00000   0.90680   0.25000   0.09000   0.00583
Al1   0.00000   0.90680   0.25000   0.07000   0.00583
Fe1   0.00000   0.90680   0.25000   0.05000   0.00583
Ca2   0.00000   0.30080   0.25000   0.78000   0.00963
Na2   0.00000   0.30080   0.25000   0.18000   0.00963
Mg2   0.00000   0.30080   0.25000   0.04000   0.00811
Si   0.28770   0.09270   0.23090   0.98500   0.00443
Al   0.28770   0.09270   0.23090   0.01500   0.00443
O1   0.11500   0.08530   0.14050   1.00000   0.00773
O2   0.36140   0.25190   0.31700   1.00000   0.00988
O3   0.35130   0.01680  -0.00190   1.00000   0.00747