data_global
_chemical_name_mineral 'Protoenstatite'
loop_
_publ_author_name
'Jahn S'
'Martonak R'
_journal_name_full 'American Mineralogist'
_journal_volume 94 
_journal_year 2009
_journal_page_first 950
_journal_page_last 956
_publ_section_title
;
 Phase behavior of protoenstatite at high pressure studied by atomistic simulations
;
_database_code_amcsd 0004955
_chemical_compound_source 'theoretical structure'
_chemical_formula_sum 'O3 Si Mg'
_cell_length_a 9.171
_cell_length_b 8.513
_cell_length_c 5.254
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 410.194
_exptl_crystal_density_diffrn      3.251
_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
O1   0.11810   0.09470   0.07920
O2   0.37580   0.25190   0.06970
O3   0.34930   0.97630   0.29280
Si   0.29130   0.09200   0.06790
Mg1   0.00000   0.09440   0.75000
Mg2   0.00000   0.26660   0.25000