data_9000304
_chemical_name 'Orthoclase'
loop_
_publ_author_name
'Phillips M W'
'Ribbe P H'
_journal_name_full "American Mineralogist"
_journal_volume 58
_journal_year 1973
_journal_page_first 263
_journal_page_last 270
_publ_section_title
;
 The structures of monoclinic potassium-rich feldspars
 Note: variety adularia
;
_chemical_formula_sum '(Si2.98 Al1.02) K O8'
_cell_length_a 8.545
_cell_length_b 12.967
_cell_length_c 7.201
_cell_angle_alpha 90
_cell_angle_beta 116.00
_cell_angle_gamma 90
_cell_volume 717.141
_symmetry_space_group_name_H-M 'C 1 2/m 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,z'
  '1/2+x,1/2-y,z'
  '-x,y,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Si1   0.00930   0.18420   0.22430   0.60000
Al1   0.00930   0.18420   0.22430   0.40000
Si2   0.70780   0.11760   0.34450   0.89000
Al2   0.70780   0.11760   0.34450   0.11000
K   0.28340   0.00000   0.13720   1.00000
OA(1)   0.00000   0.14470   0.00000   1.00000
OA(2)   0.63390   0.00000   0.28480   1.00000
OB   0.82620   0.14490   0.22800   1.00000
OC   0.03390   0.31170   0.25850   1.00000
OD   0.18210   0.12570   0.40700   1.00000