data_global
_chemical_name_mineral 'Quartz'
loop_
_publ_author_name
'Levien L'
'Prewitt C T'
'Weidner D J'
_journal_name_full 'American Mineralogist'
_journal_volume 65 
_journal_year 1980
_journal_page_first 920
_journal_page_last 930
_publ_section_title
;
 Structure and elastic properties of quartz at pressure
 P = 55.8 kbar
;
_database_code_amcsd 0000793
_chemical_formula_sum 'Si O2'
_cell_length_a 4.722
_cell_length_b 4.722
_cell_length_c 5.267
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 101.706
_exptl_crystal_density_diffrn      2.943
_symmetry_space_group_name_H-M 'P 32 2 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'y,x,2/3-z'
  '-y,x-y,2/3+z'
  '-x,-x+y,1/3-z'
  '-x+y,-x,1/3+z'
  'x-y,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.45370   0.00000   0.00000
O   0.40470   0.29260   0.09980
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 0.00695 0.00627 0.00506 0.00313 -0.00022 -0.00044
O 0.01296 0.00991 0.00871 0.00669 -0.00349 -0.00327