#------------------------------------------------------------------------------
#$Date: 2013-05-05 17:21:46 +0300 (Sun, 05 May 2013) $
#$Revision: 85285 $
#$URL: file:///home/coder/svn-repositories/cod/cif/9/00/05/9000520.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided the American Mineralogist Crystal Structure Database,
# http://rruff.geo.arizona.edu/AMS/amcsd.php
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_9000520
loop_
_publ_author_name
'Dollase, W. A.'
'Baur, W. H.'
_publ_section_title
;
 The superstructure of meteoritic low tridymite solved by computer simulation
;
_journal_name_full               'American Mineralogist'
_journal_page_first              971
_journal_page_last               978
_journal_volume                  61
_journal_year                    1976
_chemical_formula_sum            'O2 Si'
_chemical_name_mineral           Tridymite
_space_group_IT_number           9
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_cell_angle_alpha                90
_cell_angle_beta                 105.82
_cell_angle_gamma                90
_cell_length_a                   18.524
_cell_length_b                   5.0032
_cell_length_c                   23.810
_cell_volume                     2123.110
_exptl_crystal_density_diffrn    2.256
_[local]_cod_chemical_formula_sum_orig 'Si O2'
_cod_database_code               9000520
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
1/2+x,1/2+y,z
x,-y,1/2+z
1/2+x,1/2-y,1/2+z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Si1 0.55070 0.54100 0.56420 0.01140
Si2 0.70360 0.94700 0.73740 0.01520
Si3 0.41980 0.54900 0.62250 0.00887
Si4 0.57510 0.04300 0.79550 0.01393
Si5 0.92470 0.54800 0.69710 0.01013
Si6 0.76430 0.94400 0.53860 0.01140
Si7 0.80230 0.44900 0.76610 0.01013
Si8 0.64530 0.04100 0.60270 0.00887
Si9 0.85310 0.46300 0.90160 0.01267
Si10 0.94930 0.96600 0.93580 0.01267
Si11 0.72440 0.55900 0.96050 0.01140
Si12 0.56970 0.54900 0.87020 0.01393
O1 0.57490 0.35100 0.81820 0.01520
O2 0.57070 0.84000 0.84760 0.01900
O3 0.73150 0.13800 0.48510 0.02280
O4 0.75090 0.64400 0.51520 0.02153
O5 0.41550 0.35200 0.67410 0.03673
O6 0.41270 0.85200 0.64340 0.02406
O7 0.87730 0.16400 0.92130 0.02280
O8 0.91600 0.66800 0.93610 0.03040
O9 0.77410 0.14500 0.75380 0.02280
O10 0.73360 0.64300 0.74020 0.02786
O11 0.61950 0.34100 0.58470 0.01520
O12 0.58110 0.84300 0.56610 0.02406
O13 0.49660 0.51100 0.60620 0.03420
O14 0.35330 0.48900 0.56650 0.01267
O15 0.64980 0.00500 0.67110 0.02280
O16 0.65240 0.99600 0.78050 0.02533
O17 0.86360 0.49900 0.73280 0.02280
O18 0.83610 0.50300 0.83330 0.03293
O19 0.50520 0.99300 0.73980 0.02280
O20 0.63690 0.51100 0.92680 0.03673
O21 0.99270 0.99200 0.88680 0.01773
O22 0.50000 0.46800 0.50000 0.02786
O23 0.72520 0.99100 0.58980 0.02913
O24 0.77440 0.52100 0.91550 0.01900