data_global
_chemical_name_mineral 'Ferrosilite'
loop_
_publ_author_name
'Smyth J R'
_journal_name_full 'American Mineralogist'
_journal_volume 58
_journal_year 1973
_journal_page_first 636
_journal_page_last 648
_publ_section_title
;
 An orthopyroxene structure up to 850 C
 T = 175 C
 note temperature factors for O1b appear incorrect
;
_database_code_amcsd 363
_chemical_formula_sum 'Mg.635 Fe1.332 Ca.032 Si2 O6'
_cell_length_a 18.364
_cell_length_b 8.988
_cell_length_c 5.238
_cell_angle_alpha 90.0
_cell_angle_beta 90.0
_cell_angle_gamma 90.0
_cell_volume 864.561
_exptl_crystal_density_diffrn  3.738
_symmetry_space_group_name_H-M 'P b c a'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '1/2+x,y,1/2-z'
  '1/2-x,-y,1/2+z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mg1   0.3754  0.6543  0.8783  0.596
Fe1   0.3754  0.6543  0.8783  0.403
Fe2   0.3777  0.4844  0.3715  0.929
Mg2   0.3777  0.4844  0.3715  0.039
Ca2   0.3777  0.4844  0.3715  0.032
Sia   0.2719  0.3399  0.0531  1.0
Sib   0.474  0.3356  0.7917  1.0
O1a   0.1834  0.3374  0.0454  1.0
O2a   0.3114  0.498  0.0616  1.0
O3a   0.3025  0.2353  -0.1807  1.0
O1b   0.5623  0.3363  0.7879  1.0
O2b   0.4341  0.4847  0.6994  1.0
O3b   0.4477  0.2043  0.5858  1.0
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   0.00996  0.01105  0.00933  -0.0007  -0.00066  -0.00018
Fe1   0.00996  0.01105  0.00933  -0.0007  -0.00066  -0.00018
Fe2   0.01336  0.01601  0.0125  -0.00054  -0.00384  0.0001
Mg2   0.01336  0.01601  0.0125  -0.00054  -0.00384  0.0001
Ca2   0.01336  0.01601  0.0125  -0.00054  -0.00384  0.0001
Sia   0.00981  0.01  0.01232  0.0  0.0  0.0
Sib   0.01143  0.01106  0.00979  -0.00011  7e-05  0.00014
O1a   0.01237  0.01184  0.00815  -0.00058  -0.00054  -0.00162
O2a   0.01327  0.01667  0.00895  -0.00171  -0.00061  -0.00432
O3a   0.01203  0.02348  0.01647  -0.00675  0.00054  0.00439
O1b   0.00593  0.01359  0.00897  -0.00188  -0.00027  -0.0009
O2b   0.01063  0.01717  0.00965  0.00035  0.00429  -0.00217
O3b   0.00801  0.01826  0.01733  -0.00232  -0.00098  -0.00522