data_global
_chemical_name_mineral 'Cristobalite'
loop_
_publ_author_name
'Matsui M'
'Sato T'
'Funamori N'
_journal_name_full 'American Mineralogist'
_journal_volume 99 
_journal_year 2014
_journal_page_first 184
_journal_page_last 189
_publ_section_title
;
 Crystal structures and stabilities of cristobalite-helium phases at high pressures
 Note: P = 10 GPa
;
_database_code_amcsd 0020170
_chemical_compound_source 'calculated structure'
_chemical_formula_sum 'Si O2 He'
_cell_length_a 8.062
_cell_length_b 4.797
_cell_length_c 9.491
_cell_angle_alpha 90
_cell_angle_beta 120.43
_cell_angle_gamma 90
_cell_volume 316.488
_exptl_crystal_density_diffrn      2.690
_symmetry_space_group_name_H-M 'P 1 21/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-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
Si1   0.62340   0.38830   0.83820
Si2   0.87260   0.12150   0.71190
O1   0.80010   0.26410   0.82490
O2   0.69100   0.41210   0.02930
O3   0.43540   0.19120   0.74770
O4   0.03730   0.31840   0.71460
He1   0.63280   0.59350   0.53200
He2   0.13790   0.33150   0.51360