data_global
_chemical_name_mineral 'Quartz'
loop_
_publ_author_name
'Kihara K'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 2 
_journal_year 1990
_journal_page_first 63
_journal_page_last 77
_publ_section_title
;
 An X-ray study of the temperature dependence of the quartz structure
 Sample: at T = 854 K
;
_database_code_amcsd 0006371
_chemical_formula_sum 'Si O2'
_cell_length_a 4.9968
_cell_length_b 4.9968
_cell_length_c 5.4576
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 118.009
_exptl_crystal_density_diffrn      2.536
_symmetry_space_group_name_H-M 'P 62 2 2'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,x-y,1/3-z'
  'x-y,x,1/3+z'
  'y,x,2/3-z'
  '-y,x-y,2/3+z'
  '-x+y,y,-z'
  '-x,-y,z'
  '-x,-x+y,1/3-z'
  '-x+y,-x,1/3+z'
  '-y,-x,2/3-z'
  'y,-x+y,2/3+z'
  'x-y,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.50000   0.00000   0.00000
O   0.41570   0.20785   0.16667
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 0.02637 0.02030 0.01977 0.01015 0.00000 0.00000
O 0.05056 0.05474 0.05779 0.02528 0.00000 -0.03123