data_global
_chemical_name_mineral 'Pyroxene'
loop_
_publ_author_name
'Smyth J R'
'Ito J'
_journal_name_full 'American Mineralogist'
_journal_volume 62 
_journal_year 1977
_journal_page_first 1252
_journal_page_last 1257
_publ_section_title
;
 The synthesis and crystal structure of a magnesium-lithium-scandium
 protopyroxene
;
_database_code_amcsd 0000608
_chemical_formula_sum '(Mg1.4 Sc.3) Li.3 Si2 O6'
_cell_length_a 9.251
_cell_length_b 8.773
_cell_length_c 5.377
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 436.392
_exptl_crystal_density_diffrn      3.071
_symmetry_space_group_name_H-M 'P b c n'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '1/2+x,1/2+y,1/2-z'
  '1/2-x,1/2-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   0.00000   0.09940   0.75000   0.70000
Sc1   0.00000   0.09940   0.75000   0.30000
Mg2   0.00000   0.26390   0.25000   0.70000
Li2   0.00000   0.26390   0.25000   0.30000
Si   0.29350   0.09000   0.07400   1.00000
O1   0.11990   0.09080   0.08050   1.00000
O2   0.37360   0.25040   0.07100   1.00000
O3   0.34930   0.98310   0.30450   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 0.00650 0.00858 0.00542 0.00000 -0.00101 0.00000
Sc1 0.00650 0.00858 0.00542 0.00000 -0.00101 0.00000
Mg2 0.01171 0.01599 0.00776 0.00000 -0.00126 0.00000
Li2 0.01171 0.01599 0.00776 0.00000 -0.00126 0.00000
Si 0.00477 0.00858 0.00410 -0.00082 0.00025 -0.00024
O1 0.00607 0.00624 0.00513 -0.00082 -0.00025 0.00000
O2 0.01084 0.01287 0.00615 -0.00370 0.00076 0.00000
O3 0.00564 0.01248 0.00952 0.00082 -0.00101 0.00430