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 = 859 K
;
_database_code_amcsd 0006372
_chemical_formula_sum 'Si O2'
_cell_length_a 4.9973
_cell_length_b 4.9973
_cell_length_c 5.4572
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 118.024
_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   0.41530   0.20765   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 0.02647 0.02069 0.02007 0.01034 0.00000 0.00000
O 0.05019 0.05427 0.05763 0.02510 0.00000 -0.03087