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#$Date: 2011-09-17 21:27:16 +0100 (Sat, 17 Sep 2011) $
#$Revision: 26029 $
#$URL: svn://www.crystallography.net/cod/cif/2/2002892.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_2002892
_journal_name_full               'Acta Crystallographica, Section B'
_journal_volume                  54
_journal_year     1998
_journal_page_first     531
_journal_page_last     546
_publ_section_title
;
Cristobalite-related phases in the NaAlO2-NaAlSiO4 system  I.  Two tetragonal
 and two orthorhombic structures
;
loop_
    _publ_author_name
    'Thompson, John G'
    'Withers, Ray L.'
    'Melnitchenko, Alexandra'
    'Palethorpe, Stephen R.'
_chemical_formula_sum            'Al1.95 Na1.95 O4 Si0.05'
_[local]_cod_chemical_formula_sum_orig 'Na1.95 Al1.95 Si0.05 O4'
_chemical_formula_weight     162.85
_symmetry_space_group_name_H-M     'P 41 21 2'
loop_
    _symmetry_equiv_pos_as_xyz
    'x,y,z'
    '-x,-y,1/2+z'
    '1/2-y,1/2+x,1/4+z'
    '1/2+y,1/2-x,3/4+z'
    '1/2-x,1/2+y,1/4-z'
    '1/2+x,1/2-y,3/4-z'
    'y,x,-z'
    '-y,-x,1/2-z'
_cell_length_a     5.2997(6)
_cell_length_b     5.2997(6)
_cell_length_c     7.0758(9)
_cell_angle_alpha     90.0
_cell_angle_beta     90.0
_cell_angle_gamma     90.0
_cell_volume     198.74(4)
_cell_formula_units_Z     2
_cell_measurement_temperature     293
_exptl_crystal_density_diffrn     2.722
_diffrn_ambient_temperature     293
_diffrn_radiation_type     'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_radiation_source     'sealed tube'
_diffrn_radiation_monochromator     'graphite'
_diffrn_measurement_device     'Siemens D-5000'
_diffrn_measurement_method     'profile data from theta/2theta scan'
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_occupancy
    _atom_site_type_symbol
    M 0.3061(3) 0.3061(3) 0.000 0.0260(10)
                                            0.975 Al
    M 0.3061(3) 0.3061(3) 0.000 0.0260(10)
                                            0.025 Si
    Na 0.2891(4) 0.2891(4) 0.500 0.0470(10)
                                             0.975 Na
    O 0.2337(5) 0.1270(5) 0.1989(4) 0.0270(10)
                                             1.0 O
_cod_database_code 2002892