data_global
_chemical_name_mineral 'Quartz'
loop_
_publ_author_name
'Gualtieri A F'
_journal_name_full 'Journal of Applied Crystallography'
_journal_volume 33 
_journal_year 2000
_journal_page_first 267
_journal_page_last 278
_publ_section_title
;
 Accuracy of XRPD QPA using the combined Rietveld-RIR method
;
_database_code_amcsd 0012866
_chemical_compound_source 'Baveno, Novara, Italy'
_chemical_formula_sum 'Si O2'
_cell_length_a 4.9158
_cell_length_b 4.9158
_cell_length_c 5.4091
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 113.199
_exptl_crystal_density_diffrn      2.644
_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
_atom_site_U_iso_or_equiv
Si   0.53030   0.00000   0.33333   0.02200
O   0.14620   0.41420  -0.11900   0.01900