#------------------------------------------------------------------------------
#$Date: 2016-01-09 14:37:22 +0200 (Sat, 09 Jan 2016) $
#$Revision: 174125 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/54/21/1542120.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_1542120
loop_
_publ_author_name
'Grund, A.'
_publ_section_title
;
 La structure cristalline du disilicate de soude beta-Na2 Si2 O5
;
_journal_name_full
;
Bulletin de la Societe Francaise de Mineralogie et de Cristallographie 
(72,1949-100,1977)
;
_journal_page_first              775
_journal_page_last               785
_journal_volume                  77
_journal_year                    1954
_chemical_formula_sum            'Na2 O5 Si2'
_chemical_name_systematic        'Na2 (Si2 O5)'
_space_group_IT_number           14
_symmetry_space_group_name_Hall  '-P 2yab'
_symmetry_space_group_name_H-M   'P 1 21/a 1'
_cell_angle_alpha                90
_cell_angle_beta                 104.3
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   12.26
_cell_length_b                   4.8
_cell_length_c                   8.08
_cell_volume                     460.759
_citation_journal_id_ASTM        BUFCAE
_cod_data_source_file            Grund_BUFCAE_1954_66.cif
_cod_data_source_block           Na2O5Si2
_cod_cif_authors_sg_Hall         '-P 2ybc (z,y,-x)'
_cod_original_cell_volume        460.7591
_cod_database_code               1542120
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
-x+1/2,y+1/2,-z
-x,-y,-z
x-1/2,-y-1/2,z
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
O2 O-2 0.254 0.635 0.434 1 0.0
Si2 Si+4 0.278 0.3 0.406 1 0.0
O1 O-2 0.215 0.866 0.029 1 0.0
Na2 Na+1 0.465 0.235 0.136 1 0.0
Si1 Si+4 0.183 0.196 0.02 1 0.0
O5 O-2 0.434 0.735 0.09 1 0.0
O3 O-2 0.184 0.25 0.222 1 0.0
Na1 Na+1 0.435 0.765 0.39 1 0.0
O4 O-2 0.397 0.265 0.394 1 0.0