data_global
_chemical_name_mineral 'Diopside'
loop_
_publ_author_name
'Harlow G E'
_journal_name_full 'American Mineralogist'
_journal_volume 81 
_journal_year 1996
_journal_page_first 632
_journal_page_last 638
_publ_section_title
;
 Structure refinement of a natural K-rich diopside: The effect of K on the
 average structure
;
_database_code_amcsd 0001796
_chemical_formula_sum 'Mg.955 Fe.059 Al.029 Cr.071 Ca.798 K.073 Na.023 Si1.992 O6'
_cell_length_a 9.7476
_cell_length_b 8.9478
_cell_length_c 5.2622
_cell_angle_alpha 90
_cell_angle_beta 106.056
_cell_angle_gamma 90
_cell_volume 441.063
_exptl_crystal_density_diffrn      3.287
_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   0.90690   0.25000   0.88500 ?
Fe1   0.00000   0.90690   0.25000   0.02300 ?
Al1   0.00000   0.90690   0.25000   0.02100 ?
Cr1   0.00000   0.90690   0.25000   0.07100 ?
Ca2   0.00000   0.30080   0.25000   0.79800 ?
K2   0.00000   0.30080   0.25000   0.07300 ?
Na2   0.00000   0.30080   0.25000   0.02300 ?
Mg2*   0.00000   0.26400   0.25000   0.07000   0.04939
Fe2*   0.00000   0.26400   0.25000   0.03600   0.04939
Si   0.28726   0.09254   0.23000   0.99600 ?
Al   0.28726   0.09254   0.23000   0.00400 ?
O1   0.11540   0.08610   0.14150   1.00000 ?
O2   0.36210   0.24980   0.31930   1.00000 ?
O3   0.35020   0.01820   0.99510   1.00000 ?
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
Mg1 0.00720 0.00600 0.00740 0.00000 0.00030 0.00000
Fe1 0.00720 0.00600 0.00740 0.00000 0.00030 0.00000
Al1 0.00720 0.00600 0.00740 0.00000 0.00030 0.00000
Cr1 0.00720 0.00600 0.00740 0.00000 0.00030 0.00000
Ca2 0.01020 0.00930 0.00690 0.00000 -0.00200 0.00000
K2 0.01020 0.00930 0.00690 0.00000 -0.00200 0.00000
Na2 0.01020 0.00930 0.00690 0.00000 -0.00200 0.00000
Si 0.00790 0.00640 0.00890 -0.00030 0.00230 -0.00060
Al 0.00790 0.00640 0.00890 -0.00030 0.00230 -0.00060
O1 0.00890 0.01200 0.01200 0.00060 0.00230 0.00000
O2 0.01800 0.00900 0.01900 -0.00440 0.00730 -0.00270
O3 0.00780 0.01500 0.01100 -0.00020 0.00250 -0.00450