#------------------------------------------------------------------------------
#$Date: 2008-03-10 10:25:41 +0200 (Mon, 10 Mar 2008) $
#$Revision: 255 $
#$URL: file:///home/coder/svn-repositories/cod/cif/9/9005270.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_9005270
loop_
_publ_author_name
'Graetsch H'
'Topalovic-Dierdorf I'
_publ_section_title
;
 29Si MAS NMR spectrum and superstructure of modulated tridymite L3-To(MX-1)
 Sample: average crystal structure
;
_journal_name_full               'European Journal of Mineralogy'
_journal_page_first              103
_journal_page_last               113
_journal_volume                  8
_journal_year                    1996
_chemical_formula_sum            'Si O2'
_chemical_name_mineral           Tridymite
_symmetry_space_group_name_H-M   'C 1 c 1'
_cell_angle_alpha                90
_cell_angle_beta                 91.512
_cell_angle_gamma                90
_cell_length_a                   5.007
_cell_length_b                   8.6004
_cell_length_c                   8.2169
_cell_volume                     353.715
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 0.07640 0.30730 0.21080 0.05200
Si2 0.07730 0.35920 0.83520 0.05200
O1 0.28850 0.75300 0.25340 0.04400
O2 0.14400 0.46470 0.30820 0.08500
O3 0.28840 0.17970 0.27030 0.13800
O4 0.58260 0.16680 0.51980 0.18800
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
Si1 0.04300 0.03300 0.08000 0.00400 0.03100 0.00600
Si2 0.04200 0.03400 0.08200 0.00400 0.03100 0.00800
O1 0.03900 0.04700 0.04600 0.01000 0.00100 -0.00300
O2 0.04800 0.03000 0.17600 -0.01400 -0.01700 0.00900
O3 0.03200 0.03200 0.35000 0.00800 -0.00200 0.00800
O4 0.26600 0.21600 0.09000 -0.02300 0.13200 -0.01400