data_9001795
_chemical_name 'Leucite'
loop_
_publ_author_name
'Palmer D C'
'Dove M T'
'Ibberson R M'
'Powell B M'
_journal_name_full "American Mineralogist"
_journal_volume 82
_journal_year 1997
_journal_page_first 16
_journal_page_last 29
_publ_section_title
;
 Structural behavior, crystal chemistry and phase transitions in substituted
 leucites: High-resolution neutron powder diffraction studies
 Sample: Natural, Expt. no. 3003, T = 298 K, KAlSi2O6
;
_chemical_formula_sum 'K (Si2 Al) O6'
_cell_length_a 13.05476
_cell_length_b 13.05476
_cell_length_c 13.75182
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 2343.678
_symmetry_space_group_name_H-M 'I 41/a'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '3/4+y,1/4-x,1/4-z'
  '1/4+y,3/4-x,3/4-z'
  '3/4-y,1/4+x,1/4+z'
  '1/4-y,3/4+x,3/4+z'
  '1/2+x,y,1/2-z'
  '+x,1/2+y,-z'
  '1/2-x,-y,1/2+z'
  '-x,1/2-y,+z'
  '3/4-y,3/4+x,3/4-z'
  '1/4-y,1/4+x,1/4-z'
  '3/4+y,3/4-x,3/4+z'
  '1/4+y,1/4-x,1/4+z'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
K   0.36590   0.36370   0.11690   1.00000
Si1   0.05740   0.39690   0.16650   0.66667
Si2   0.16750   0.61160   0.12870   0.66667
Si3   0.39300   0.64200   0.08620   0.66667
Al1   0.05740   0.39690   0.16650   0.33333
Al2   0.16750   0.61160   0.12870   0.33333
Al3   0.39300   0.64200   0.08620   0.33333
O1   0.13240   0.31410   0.10990   1.00000
O2   0.09080   0.51120   0.13080   1.00000
O3   0.14610   0.68080   0.22780   1.00000
O4   0.13310   0.68510   0.03480   1.00000
O5   0.28890   0.57560   0.12040   1.00000
O6   0.48360   0.61720   0.16730   1.00000