#------------------------------------------------------------------------------
#$Date: 2023-03-27 16:24:39 +0300 (Mon, 27 Mar 2023) $
#$Revision: 282075 $
#$URL: file:///home/coder/svn-repositories/cod/cif/8/10/45/8104534.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_8104534
loop_
_publ_author_name
'Kihara, K.'
'Matsumoto, T.'
'Imamura, M.'
_publ_section_title
;
 Structural change of orthorhombic-I tridymite with temperature: A study
 based on second-order thermal-vibrational parameters : structure at 443 K
;
_journal_name_full               'Zeitschrift fur Kristallographie'
_journal_page_first              27
_journal_page_last               38
_journal_volume                  177
_journal_year                    1986
_journal_paper_doi               10.1524/zkri.1986.177.1-2.27
_chemical_formula_sum            'O2 Si'
_chemical_name_common            tridymite
_chemical_name_mineral           'tridymite OC at 443 K'
_space_group_IT_number           20
_space_group_name_H-M_alt        'C 2 2 21'
_symmetry_space_group_name_Hall  'C 2c 2'
_symmetry_space_group_name_H-M   'C 2 2 21'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   8.730(11)
_cell_length_b                   5.000(6)
_cell_length_c                   8.201(6)
_cell_volume                     358.0(7)
_diffrn_ambient_temperature      443
_cod_data_source_file            tridymite-OC-443K.cif
_cod_data_source_block           tridymite-OC-443K
_cod_depositor_comments
;I added measured temperature tag as there are a series of structures
 with different temperatures.
;
_cod_original_formula_sum        'Si O2'
_cod_database_code               8104534
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, z+1/2'
'-x, y, -z+1/2'
'x, -y, -z'
'x+1/2, y+1/2, z'
'-x+1/2, -y+1/2, z+1/2'
'-x+1/2, y+1/2, -z+1/2'
'x+1/2, -y+1/2, -z'
loop_
_atom_site_label
_atom_site_occupancy
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_adp_type
_atom_site_B_iso_or_equiv
_atom_site_type_symbol
Si 1.0 0.1685(4) 0.5512(8) 0.1880(5) Biso 2.943084 Si
O1 1.0 0.327(3) 0.000000 0.500000 Biso 7.002168 O
O2 1.0 0.000000 0.5774(65) 0.250000 Biso 8.254930 O
O3 1.0 0.2503(23) 0.3182(36) 0.2801(20) Biso 8.624811 O
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 0.02934 0.04534 0.03714 0.00177 0.00472 -0.00436
O1 0.09575 0.13248 0.03782 0.00000 0.00000 0.01724
O2 0.03243 0.16946 0.11176 0.00000 -0.01959 0.00000
O3 0.13320 0.10727 0.08723 0.06037 0.00254 0.01184
