data_global
_chemical_name_mineral 'Nepheline'
loop_
_publ_author_name
'Angel R J'
'Gatta G C'
'Boffa Ballaran T'
'Carpenter M A'
_journal_name_full 'The Canadian Mineralogist'
_journal_volume 46 
_journal_year 2008
_journal_page_first 1465
_journal_page_last 1476
_publ_section_title
;
 The mechanism of coupling in the modulated structure of nepheline
 Note: annealed
 Note: T = 100 K
;
_database_code_amcsd 0006207
_chemical_compound_source 'Snipe River, Tambani, Malawi'
_chemical_formula_sum 'K.57 Na3.24 (Al3.84 Si4.16) O16'
_cell_length_a 9.9685
_cell_length_b 9.9685
_cell_length_c 8.3608
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 719.512
_exptl_crystal_density_diffrn      2.646
_symmetry_space_group_name_H-M 'P 63'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x-y,x,1/2+z'
  '-y,x-y,z'
  '-x,-y,1/2+z'
  '-x+y,-x,z'
  'y,-x+y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
K   0.00000   0.00000   0.00280   0.57000   0.02200
Na1   0.00000   0.00000   0.00280   0.24000   0.02200
Na2   0.55510   0.99760   0.50850   1.00000   0.01500
Al1   0.66667   0.33333   0.70170   0.48000   0.00900
Si1   0.66667   0.33333   0.70170   0.52000   0.00900
Al2   0.66667   0.33333   0.31240   0.48000   0.01000
Si2   0.66667   0.33333   0.31240   0.52000   0.01000
Al3   0.90670   0.66610   0.82250   0.48000   0.01000
Si3   0.90670   0.66610   0.82250   0.52000   0.01000
Al4   0.90740   0.66750   0.19580   0.48000   0.00800
Si4   0.90740   0.66750   0.19580   0.52000   0.00800
O1   0.66050   0.28460   0.50080   0.33333   0.02100
O2   0.97430   0.68300   0.00230   1.00000   0.02900
O3   0.82730   0.47710   0.25180   1.00000   0.03300
O4   0.83790   0.48940   0.76240   1.00000   0.03400
O5   0.77360   0.71410   0.82570   1.00000   0.01400
O6   0.77690   0.73330   0.20110   1.00000   0.01500