#------------------------------------------------------------------------------
#$Date: 2008-01-13 22:15:36 +0000 (Sun, 13 Jan 2008) $
#$Revision: 14 $
#$URL: svn://www.crystallography.net/cod/cif/2/2002894.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_2002894
_journal_name_full     'Acta Crystallographica, Section B'
_journal_year     1998
_journal_volume     B54
_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     'Na1.65 Al1.65 Si0.35 O4'
_chemical_formula_weight     156.28
_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     10.3872(7)
_cell_length_b     10.3872(7)
_cell_length_c     7.1589(8)
_cell_angle_alpha     90.0
_cell_angle_beta     90.0
_cell_angle_gamma     90.0
_cell_volume     772.40(10)
_cell_formula_units_Z     8
_cell_measurement_temperature     293
_exptl_crystal_density_diffrn     2.688
_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
    M1 0.1530(10)
                0.1530(10)
                         0.000(-) 0.825 0.034(2) Al
    M1 0.1530(10)
                0.1530(10)
                         0.000(-) 0.175 0.034(2) Si
    M2 0.3990(10)
                0.3990(10)
                         0.500(-) 0.825 0.034(2) Al
    M2 0.3990(10)
                0.3990(10)
                         0.500(-) 0.175 0.034(2) Si
    M3 0.3940(10)
                0.1400(10)
                         0.263(2) 0.825 0.034(2) Al
    M3 0.3940(10)
                0.1400(10)
                         0.263(2) 0.175 0.034(2) Si
    Na1 0.164(2) 0.164(2) 0.500(-) 0.84(2)   ? Na
    Na2 0.4000(10)
                 0.4000(10)
                          0.000(-) 0.704(19) ? Na
    Na3 0.385(2) 0.099(2) 0.745(8) 0.844(15) ? Na
    O1 0.0670(10)
                0.118(2) 0.202(2) 1.0 0.128(5) O
    O2 0.3140(10)
                0.129(2) 0.052(3) 1.0 0.128(5) O
    O3 0.3010(10)
                0.357(2) 0.683(2) 1.0 0.128(5) O
    O4 0.0510(10)
                0.339(2) 0.556(3) 1.0 0.128(5) O