data_9002507
_chemical_name 'TAPP'
loop_
_publ_author_name
'Finger L W'
'Conrad P G'
_journal_name_full "American Mineralogist"
_journal_volume 85
_journal_year 2000
_journal_page_first 1804
_journal_page_last 1807
_publ_section_title
;
 The crystal structure of "Tetragonal Almandine-Pyrope Phase" (TAPP):
 A reexamination
;
_chemical_formula_sum 'Si2.91 Al1.942 Fe.49 Mg2.658 O12'
_cell_length_a 6.5269
_cell_length_b 6.5269
_cell_length_c 18.1835
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 774.625
_symmetry_space_group_name_H-M 'I -4 2 d'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/2-y,-x,3/4+z'
  '-y,1/2-x,1/4+z'
  'y,-x,-z'
  '1/2+y,1/2-x,1/2-z'
  '-x,1/2+y,1/4-z'
  '1/2-x,+y,3/4-z'
  '-x,-y,z'
  '1/2-x,1/2-y,1/2+z'
  '1/2+y,x,3/4+z'
  '+y,1/2+x,1/4+z'
  '-y,x,-z'
  '1/2-y,1/2+x,1/2-z'
  'x,1/2-y,1/4-z'
  '1/2+x,-y,3/4-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Si1   0.50000   0.50000   0.00000   1.00000
Si2  -0.14990   0.25000   0.12500   0.95500
Al2  -0.14990   0.25000   0.12500   0.04500
Fe1   0.00000   0.00000   0.00000   0.21000
Mg1   0.00000   0.00000   0.00000   0.79000
Fe2   0.25990   0.25000   0.12500   0.07400
Al2   0.25990   0.25000   0.12500   0.92600
Fe3   0.00000   0.50000  -0.02296   0.06600
Mg3   0.00000   0.50000  -0.02296   0.93400
O1   0.01870   0.28090   0.05760   1.00000
O2  -0.26140   0.03720   0.10130   1.00000
O3   0.43680   0.29610   0.04680   1.00000