data_1011205
_chemical_name_systematic          'Potassium tecto-alumotrisilicate'
_chemical_name_mineral             'Orthoclase'
_chemical_compound_source          'from Mogok, Upper Burma, (Spencer C)'
_chemical_formula_structural       'K (Al Si3 O8)'
_chemical_formula_analytical       '(K.91 Na.07 Ca.02) (Al1.02 Si2.98) O8'
_chemical_formula_sum              'Al K O8 Si3'
_publ_section_title                'The structure of orthoclase.'
loop_
_publ_author_name
  'Chao, S H'
  'Hargreaves, A'
  'Taylor, W H'
_journal_name_full
;
Mineralogical Magazine and Journal of the Mineralogical Society (1876-
1968)
;
_journal_coden_ASTM                MIASA6
_journal_volume                    25
_journal_year                      1940
_journal_page_first                498
_journal_page_last                 512
_cell_length_a                     8.6
_cell_length_b                     13.02
_cell_length_c                     7.22
_cell_angle_alpha                  90
_cell_angle_beta                   116.05
_cell_angle_gamma                  90
_cell_volume                       726.3
_cell_formula_units_Z              4
_exptl_crystal_density_meas        2.56
_symmetry_space_group_name_H-M     'C 1 2/m 1'
_symmetry_Int_Tables_number        12
_symmetry_cell_setting             monoclinic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  'x,-y,z'
  '-x,-y,-z'
  '-x,y,-z'
  '1/2+x,1/2+y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2-y,-z'
  '1/2-x,1/2+y,-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  K1+    1.000
  Si4+   4.000
  Al3+   3.000
  O2-   -2.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  K1    K1+    4 i 0.2917 0. 0.1389 1.  0 d
  Si1   Si4+   8 j 0.7097 0.1167 0.347 1.  0 d
  Al2   Al3+   8 j 0.0097 0.1875 0.225 0.5  0 d
  Si2   Si4+   8 j 0.0097 0.1875 0.225 0.5  0 d
  O1    O2-    4 g 0. 0.1528 0. 1.  0 d
  O2    O2-    4 i 0.6667 0. 0.3028 1.  0 d
  O3    O2-    8 j 0.8194 0.1528 0.2278 1.  0 d
  O4    O2-    8 j 0.0417 0.3167 0.2611 1.  0 d
  O5    O2-    8 j 0.1722 0.1278 0.4167 1.  0 d