data_global
_chemical_name 'Quartz'
loop_
_publ_author_name
'Glinnemann J'
'King H E'
'Schulz H'
'Hahn T'
'La Placa S J'
'Dacol F'
_journal_name_full "Zeitschrift fur Kristallographie"
_journal_volume 198 
_journal_year 1992
_journal_page_first 177
_journal_page_last 212
_publ_section_title
;Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure

 P = 10.2GPa = 102 kbar
;
_chemical_formula_sum 'Si O2'
_cell_length_a 4.604
_cell_length_b 4.604
_cell_length_c 5.207
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 95.585
_symmetry_space_group_name_H-M 'P 31 2 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'y,x,1/3-z'
  '-y,x-y,1/3+z'
  '-x,-x+y,2/3-z'
  '-x+y,-x,2/3+z'
  'x-y,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.44580   0.00000   0.00000
O   0.39510   0.30310  -0.09210
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 0.00520 0.00390 0.00480 0.00195 0.00030 0.00060
O 0.01060 0.00720 0.00760 0.00610 0.00170 0.00200

