data_global
_chemical_name_mineral 'Quartz'
loop_
_publ_author_name
'Arnold H'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 117 
_journal_year 1962
_journal_page_first 467
_journal_page_last 469
_publ_section_title
;
 Die struktur des hochquarzes
 Note: sample is at T = 650 deg C, under the false assumption that it is twinned
;
_database_code_amcsd 0010605
_chemical_formula_sum 'Si O2'
_cell_length_a 5.01
_cell_length_b 5.01
_cell_length_c 5.47
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 118.903
_exptl_crystal_density_diffrn      2.517
_symmetry_space_group_name_H-M 'P 31 2 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'y,x,-z'
  '-y,x-y,1/3+z'
  '-x,-x+y,1/3-z'
  '-x+y,-x,2/3+z'
  'x-y,-y,2/3-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.46660   0.00000   0.33333
O   0.42750   0.18740   0.12870
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
Si 0.00315 0.00315 0.00379 0.00114 -0.00289 -0.00577
O 0.00353 0.00353 0.02713 0.00095 -0.00120 0.00036