data_global
_chemical_name_mineral 'Omphacite'
loop_
_publ_author_name
'Clark J R'
'Papike J J'
_journal_name_full 'American Mineralogist'
_journal_volume 53 
_journal_year 1968
_journal_page_first 840
_journal_page_last 868
_publ_section_title
;
 Crystal-chemical characterization of omphacites
;
_database_code_amcsd 0000175
_chemical_formula_sum 'Si4 Mg.805 Fe.31 Al.885 (Na.835 Ca1.165) O12'
_cell_length_a 9.596
_cell_length_b 8.771
_cell_length_c 5.265
_cell_angle_alpha 90
_cell_angle_beta 106.93
_cell_angle_gamma 90
_cell_volume 423.932
_exptl_crystal_density_diffrn      3.376
_symmetry_space_group_name_H-M 'P 1 2 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,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
Si1A   0.28900   0.09720   0.97740   1.00000   0.00215
Si2A   0.28810   0.91350   0.48200   1.00000   0.00215
Si1C   0.21370   0.58800   0.01960   1.00000   0.00215
Si2C   0.21030   0.40270   0.52320   1.00000   0.00215
Mg1   0.00000   0.91220   0.00000   0.81000   0.00253
Fe1   0.00000   0.91220   0.00000   0.19000   0.00253
Al11   0.00000   0.10020   0.50000   0.95000   0.00380
Fe11   0.00000   0.10020   0.50000   0.05000   0.00380
Al1H   0.50000   0.40450   0.00000   0.82000   0.00380
Fe1H   0.50000   0.40450   0.00000   0.18000   0.00380
Mg11H   0.50000   0.59570   0.50000   0.80000   0.00253
Fe11H   0.50000   0.59570   0.50000   0.20000   0.00253
Na2   0.00000   0.30360   0.00000   0.64000   0.01013
Ca2   0.00000   0.30360   0.00000   0.36000   0.01013
Na21   0.00000   0.70170   0.50000   0.36000   0.00887
Ca21   0.00000   0.70170   0.50000   0.64000   0.00887
Na2H   0.50000   0.80090   0.00000   0.03000   0.01013
Ca2H   0.50000   0.80090   0.00000   0.97000   0.01013
Na21H   0.50000   0.19960   0.50000   0.64000   0.01013
Ca21H   0.50000   0.19960   0.50000   0.36000   0.01013
O11A   0.11200   0.08800   0.86400   1.00000   0.00507
O12A   0.11000   0.92200   0.40500   1.00000   0.00507
O11C   0.38600   0.56700   0.10300   1.00000   0.00507
O12C   0.38500   0.41100   0.62000   1.00000   0.00507
O21A   0.36400   0.26300   0.06600   1.00000   0.00507
O22A   0.34700   0.74700   0.55100   1.00000   0.00507
O21C   0.13300   0.74900   0.93900   1.00000   0.00507
O22C   0.13500   0.24400   0.44600   1.00000   0.00507
O31A   0.36000   0.02200   0.75700   1.00000   0.00507
O32A   0.35000   0.99400   0.25200   1.00000   0.00507
O31C   0.15400   0.51500   0.25500   1.00000   0.00507
O32C   0.14700   0.48900   0.75000   1.00000   0.00507