data_global
_chemical_name_mineral 'Silicon'
loop_
_publ_author_name
'McMahon M I'
'Nelmes R J'
_journal_name_full 'Physical Review'
_journal_volume B47 
_journal_year 1993
_journal_page_first 8337
_journal_page_last 8340
_publ_section_title
;
 New high-pressure phase of Si
 Sample: structure exists between 13 GPa to 18 GPa
 Note: intermediate structure between those of Si II and Si V
;
_database_code_amcsd 0015170
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Si'
_cell_length_a 4.737
_cell_length_b 4.502
_cell_length_c 2.550
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 54.381
_exptl_crystal_density_diffrn      3.430
_symmetry_space_group_name_H-M 'I m m a'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  'x,1/2-y,z'
  '1/2+x,-y,1/2+z'
  '-x,1/2+y,-z'
  '1/2-x,+y,1/2-z'
  '-x,y,z'
  '1/2-x,1/2+y,1/2+z'
  'x,-y,-z'
  '1/2+x,1/2-y,1/2-z'
  'x,1/2+y,-z'
  '1/2+x,+y,1/2-z'
  '-x,1/2-y,z'
  '1/2-x,-y,1/2+z'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.00000   0.25000   0.19300