#------------------------------------------------------------------------------
#$Date: 2016-02-14 16:26:36 +0200 (Sun, 14 Feb 2016) $
#$Revision: 176435 $
#$URL: svn://www.crystallography.net/cod/cif/2/10/17/2101703.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided by IUCr Journals, http://journals.iucr.org/.
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_2101703
loop_
_publ_author_name
'Withers, Ray L.'
'Lobo, Charlene'
'Thompson, John G.'
'Schmid, Siegbert'
_publ_section_title
;
 A Modulation Wave Approach to the Structural Characterization of Three
 New Cristobalite-Related Sodium Magnesiosilicates
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              203
_journal_page_last               220
_journal_paper_doi               10.1107/S0108768196012335
_journal_volume                  53
_journal_year                    1997
_chemical_formula_sum            'Mg0.9 Na1.8 O4 Si1.1'
_chemical_formula_weight         158.15
_chemical_name_systematic
;
Sodium magnesiosilicate
;
_space_group_IT_number           92
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4abw 2nw'
_symmetry_space_group_name_H-M   'P 41 21 2'
_cell_angle_alpha                90.0
_cell_angle_beta                 90.0
_cell_angle_gamma                90.0
_cell_formula_units_Z            2
_cell_length_a                   5.330(6)
_cell_length_b                   5.330(6)
_cell_length_c                   7.086(5)
_cell_measurement_temperature    293
_cell_volume                     201.3(4)
_computing_data_collection       'Siemens ...?'
_computing_structure_refinement  GSAS
_diffrn_ambient_temperature      293
_diffrn_measurement_device       'Siemens D-5000'
_diffrn_measurement_method       2θ/θ
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_theta_max         40.0
_diffrn_reflns_theta_min         5.0
_exptl_absorpt_coefficient_mu    7.544
_exptl_absorpt_correction_type   analytical
_exptl_crystal_density_diffrn    2.609
_exptl_crystal_F_000             155.94
_cod_data_source_file            ab0354.cif
_cod_data_source_block           Na1point8
_cod_original_cell_volume        201.3(2)
_cod_original_formula_sum        'Na1.8 Mg0.9 Si1.1 O4'
_cod_database_code               2101703
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
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
Mg 0.3040(10) 0.3040(10) 0.0 0.038(4) 0.45 Mg
Si 0.3040(10) 0.3040(10) 0.0 0.038(4) 0.55 Si
Na 0.2870(10) 0.2870(10) 0.5 0.075(5) 0.9 Na
O 0.234(2) 0.1260(10) 0.1970(10) 0.046(5) 1 O
