data_9000397
_chemical_name 'Tschermakite'
loop_
_publ_author_name
'Okamura F P'
'Ghose S'
'Ohashi H'
_journal_name_full "American Mineralogist"
_journal_volume 59
_journal_year 1974
_journal_page_first 549
_journal_page_last 557
_publ_section_title
;
 Structure and crystal chemistry of calcium Tschermak's pyroxene, CaAlAlSiO6
;
_chemical_formula_sum 'Si Al2 Ca O6'
_cell_length_a 9.609
_cell_length_b 8.652
_cell_length_c 5.274
_cell_angle_alpha 90
_cell_angle_beta 106.06
_cell_angle_gamma 90
_cell_volume 421.353
_symmetry_space_group_name_H-M 'C 1 2/c 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-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
Si   0.28802   0.09693   0.21337   0.50000
Al   0.28802   0.09693   0.21337   0.50000
Al1   0.00000   0.90934   0.25000   1.00000
Ca2   0.00000   0.31117   0.25000   1.00000
O1   0.10519   0.08210   0.12264   1.00000
O2   0.36571   0.26707   0.30988   1.00000
O3   0.35524   0.01881   0.97977   1.00000