data_2002498
_chemical_name_systematic          'Aluminium tantalum oxide'
_chemical_formula_structural       'Al Ta O4'
_chemical_formula_sum              'Al O4 Ta'
_publ_section_title                'Al Ta O4 mit Al Nb O4-Struktur'
loop_
_publ_author_name
  'Harneit, O'
  'Mueller-Buschbaum, Hk'
_journal_name_full
;
Zeitschrift fuer Anorganische und Allgemeine Chemie
;
_journal_volume                    596
_journal_year                      1991
_journal_page_first                107
_journal_page_last                 110
_cell_length_a                     12.135(3)
_cell_length_b                     3.776(1)
_cell_length_c                     6.449(2)
_cell_angle_alpha                  90
_cell_angle_beta                   107.74(2)
_cell_angle_gamma                  90
_cell_volume                       281.5
_cell_formula_units_Z              4
_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
  Ta5+   5.000
  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
  Ta1   Ta5+   4 i 0.1055(1) 0. 0.2327(1) 1.  0 d
  Al1   Al3+   4 i 0.1996(6) 0. 0.8176(12) 1.  0 d
  O1    O2-    4 i 0.141(2) 0. 0.526(3) 1.  0 d
  O2    O2-    4 i 0.262(2) 0. 0.140(3) 1.  0 d
  O3    O2-    4 i 0.058(2) 0. 0.866(3) 1.  0 d
  O4    O2-    4 i 0.640(2) 0. 0.200(3) 1.  0 d
_refine_ls_R_factor_all            0.069