data_global
_chemical_name_mineral 'Diopside'
loop_
_publ_author_name
'Bertolo S'
'Nimis P'
'Dal Negro A'
_journal_name_full 'American Mineralogist'
_journal_volume 79 
_journal_year 1994
_journal_page_first 668
_journal_page_last 674
_publ_section_title
;
 Low-Ca augite from experimental alkali basalt at 18 kbar: Structural variation
 near the miscibility gap
 Atomic parameters from ICSD
;
_database_code_amcsd 0001667
_chemical_formula_sum '(Ca.774 Na.226) Mg.901 Fe.11 Si2 O6'
_cell_length_a 9.689
_cell_length_b 8.824
_cell_length_c 5.280
_cell_angle_alpha 90
_cell_angle_beta 107.60
_cell_angle_gamma 90
_cell_volume 430.287
_exptl_crystal_density_diffrn      3.341
_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
Ca   0.00000   0.28740   0.25000   0.77400 ?
Na   0.00000   0.28740   0.25000   0.22600 ?
Mg   0.00000   0.90560   0.25000   0.90100 ?
Fe1   0.00000   0.90560   0.25000   0.09900 ?
Si   0.29170   0.09180   0.24140   1.00000 ?
O1   0.11540   0.08680   0.14130   1.00000 ?
O2   0.36790   0.25220   0.33290   1.00000 ?
O3   0.35340   0.01740   0.00880   1.00000 ?
Fe2   0.00000   0.22290   0.25000   0.01100   0.02500
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
Ca 0.02080 0.03250 0.01960 0.00000 0.00200 0.00000
Na 0.02080 0.03250 0.01960 0.00000 0.00200 0.00000
Mg 0.01300 0.01060 0.01620 0.00000 0.00360 0.00000
Fe1 0.01300 0.01060 0.01620 0.00000 0.00360 0.00000
Si 0.01330 0.01100 0.02070 -0.00020 0.00560 -0.00120
O1 0.01430 0.01700 0.02170 0.00190 0.00490 -0.00100
O2 0.02690 0.01450 0.03340 -0.00420 0.01430 -0.00640
O3 0.01470 0.03680 0.03660 -0.00080 0.00590 -0.01910