data_global
_chemical_name_mineral 'Boron'
loop_
_publ_author_name
'Zarechnaya E Y'
'Dubrovinsky L'
'Dubrovinskaia N'
'Filinchuk Y'
'Chernyshov D'
'Dmitriev V'
'Miyajima N'
'El Goresy A'
'Braun H F'
'Van Smaalen S'
'Kantor I'
'Kantor A'
'Prakapenka V'
'Hanfland M'
'Mikhaylushkin A S'
'Abrikosov I A'
'Simak S I'
_journal_name_full 'Physical Review Letters'
_journal_volume 102 
_journal_year 2009
_journal_page_first 185501
_journal_page_last 1185501-4
_publ_section_title
;
 Superhard semiconducting optically transparent high pressure phase of boron
 Note: crystal quenched from 20 GPa, 1700 K
;
_database_code_amcsd 0015285
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'B7'
_cell_length_a 5.0576
_cell_length_b 5.6245
_cell_length_c 6.9884
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 198.795
_exptl_crystal_density_diffrn      2.529
_symmetry_space_group_name_H-M 'P n n m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,1/2+z'
  '1/2+x,1/2-y,1/2-z'
  'x,y,-z'
  '-x,-y,z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
B1   0.15390   0.59380   0.79240
B2   0.64690   0.72840   0.50000
B3   0.33620   0.50760   0.00000
B4   0.83910   0.71890   0.87370
B5   0.66900   0.98230   0.00000