The material described by Ca3Ta6(FeO6)4 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CaO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Ta(2)O4 tetrahedra, corners with two equivalent Ta(3)O4 tetrahedra, and edges with two equivalent Ta(1)O5 tetrahedra. The corner-sharing octahedral tilt angles are 61°. In the second Ca site, Ca(2) is bonded in a distorted pentagonal planar geometry to one O(11), one O(2), one O(5), one O(6), and one O(7) atom. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(10), one O(11), one O(2), one O(3), and one O(6) atom to form distorted TaO5 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Ta(3)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-57°. In the second Ta site, Ta(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form distorted TaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-62°. In the third Ta site, Ta(3) is bonded to one O(12), one O(2), one O(5), and one O(9) atom to form TaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one Ta(1)O5 tetrahedra. The corner-sharing octahedral tilt angles range from 16-72°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ta(3)O4 tetrahedra, corners with two equivalent Ta(1)O5 tetrahedra, corners with three equivalent Ta(2)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Ta(2)O4 tetrahedra, corners with two equivalent Ta(3)O4 tetrahedra, corners with two equivalent Ta(1)O5 tetrahedra, and  an edgeedge with one Fe(2)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one Ta(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ta(1), and one Ta(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Ta(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ta(3), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ca(2), one Ta(1), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ca(2), one Ta(2), and one Fe(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Fe(2) atoms. In the ninth O site, O(9) is bonded in a linear geometry to one Ta(3) and one Fe(1) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Ta(1) and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one Ta(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Ta(3) and one Fe(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta6(FeO6)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.027
_cell_length_b   8.686
_cell_length_c   10.648
_cell_angle_alpha   107.420
_cell_angle_beta   103.487
_cell_angle_gamma   107.246
_symmetry_Int_Tables_number   1
_cell_volume   554.001
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.316  0.310  0.809  1.0
  Ca  Ca2  1  0.684  0.690  0.191  1.0
  Ta  Ta3  1  0.822  0.342  0.743  1.0
  Ta  Ta4  1  0.178  0.658  0.257  1.0
  Ta  Ta5  1  0.877  0.906  0.668  1.0
  Ta  Ta6  1  0.398  0.756  0.869  1.0
  Ta  Ta7  1  0.123  0.094  0.332  1.0
  Ta  Ta8  1  0.602  0.244  0.131  1.0
  Fe  Fe9  1  0.375  0.957  0.600  1.0
  Fe  Fe10  1  0.625  0.043  0.400  1.0
  Fe  Fe11  1  0.035  0.193  0.015  1.0
  Fe  Fe12  1  0.965  0.807  0.985  1.0
  O  O13  1  0.825  0.680  0.575  1.0
  O  O14  1  0.175  0.320  0.425  1.0
  O  O15  1  0.208  0.522  0.759  1.0
  O  O16  1  0.792  0.478  0.241  1.0
  O  O17  1  0.798  0.285  0.553  1.0
  O  O18  1  0.202  0.715  0.447  1.0
  O  O19  1  0.657  0.962  0.569  1.0
  O  O20  1  0.343  0.038  0.431  1.0
  O  O21  1  0.639  0.739  0.982  1.0
  O  O22  1  0.361  0.261  0.018  1.0
  O  O23  1  0.453  0.783  0.269  1.0
  O  O24  1  0.547  0.217  0.731  1.0
  O  O25  1  0.135  0.020  0.649  1.0
  O  O26  1  0.080  0.064  0.140  1.0
  O  O27  1  0.920  0.936  0.860  1.0
  O  O28  1  0.578  0.148  0.264  1.0
  O  O29  1  0.422  0.852  0.736  1.0
  O  O30  1  0.143  0.434  0.152  1.0
  O  O31  1  0.857  0.566  0.848  1.0
  O  O32  1  0.988  0.244  0.837  1.0
  O  O33  1  0.012  0.756  0.163  1.0
  O  O34  1  0.258  0.848  0.979  1.0
  O  O35  1  0.742  0.152  0.021  1.0
  O  O36  1  0.865  0.980  0.351  1.0
[/CIF]
.
The material described by Ca3Ta6(FeO6)4 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CaO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Ta(2)O4 tetrahedra, corners with two equivalent Ta(3)O4 tetrahedra, and edges with two equivalent Ta(1)O5 tetrahedra. The corner-sharing octahedral tilt angles are 61°. In the second Ca site, Ca(2) is bonded in a distorted pentagonal planar geometry to one O(11), one O(2), one O(5), one O(6), and one O(7) atom. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(10), one O(11), one O(2), one O(3), and one O(6) atom to form distorted TaO5 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Ta(3)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-57°. In the second Ta site, Ta(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form distorted TaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-62°. In the third Ta site, Ta(3) is bonded to one O(12), one O(2), one O(5), and one O(9) atom to form TaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and  a cornercorner with one Ta(1)O5 tetrahedra. The corner-sharing octahedral tilt angles range from 16-72°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ta(3)O4 tetrahedra, corners with two equivalent Ta(1)O5 tetrahedra, corners with three equivalent Ta(2)O4 tetrahedra, and  an edgeedge with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Ta(2)O4 tetrahedra, corners with two equivalent Ta(3)O4 tetrahedra, corners with two equivalent Ta(1)O5 tetrahedra, and  an edgeedge with one Fe(2)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one Ta(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ta(1), and one Ta(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Ta(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ta(3), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ca(2), one Ta(1), and one Fe(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ca(2), one Ta(2), and one Fe(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Fe(2) atoms. In the ninth O site, O(9) is bonded in a linear geometry to one Ta(3) and one Fe(1) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Ta(1) and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one Ta(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Ta(3) and one Fe(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta6(FeO6)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.027
_cell_length_b   8.686
_cell_length_c   10.648
_cell_angle_alpha   107.420
_cell_angle_beta   103.487
_cell_angle_gamma   107.246
_symmetry_Int_Tables_number   1
_cell_volume   554.001
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.316  0.310  0.809  1.0
  Ca  Ca2  1  0.684  0.690  0.191  1.0
  Ta  Ta3  1  0.822  0.342  0.743  1.0
  Ta  Ta4  1  0.178  0.658  0.257  1.0
  Ta  Ta5  1  0.877  0.906  0.668  1.0
  Ta  Ta6  1  0.398  0.756  0.869  1.0
  Ta  Ta7  1  0.123  0.094  0.332  1.0
  Ta  Ta8  1  0.602  0.244  0.131  1.0
  Fe  Fe9  1  0.375  0.957  0.600  1.0
  Fe  Fe10  1  0.625  0.043  0.400  1.0
  Fe  Fe11  1  0.035  0.193  0.015  1.0
  Fe  Fe12  1  0.965  0.807  0.985  1.0
  O  O13  1  0.825  0.680  0.575  1.0
  O  O14  1  0.175  0.320  0.425  1.0
  O  O15  1  0.208  0.522  0.759  1.0
  O  O16  1  0.792  0.478  0.241  1.0
  O  O17  1  0.798  0.285  0.553  1.0
  O  O18  1  0.202  0.715  0.447  1.0
  O  O19  1  0.657  0.962  0.569  1.0
  O  O20  1  0.343  0.038  0.431  1.0
  O  O21  1  0.639  0.739  0.982  1.0
  O  O22  1  0.361  0.261  0.018  1.0
  O  O23  1  0.453  0.783  0.269  1.0
  O  O24  1  0.547  0.217  0.731  1.0
  O  O25  1  0.135  0.020  0.649  1.0
  O  O26  1  0.080  0.064  0.140  1.0
  O  O27  1  0.920  0.936  0.860  1.0
  O  O28  1  0.578  0.148  0.264  1.0
  O  O29  1  0.422  0.852  0.736  1.0
  O  O30  1  0.143  0.434  0.152  1.0
  O  O31  1  0.857  0.566  0.848  1.0
  O  O32  1  0.988  0.244  0.837  1.0
  O  O33  1  0.012  0.756  0.163  1.0
  O  O34  1  0.258  0.848  0.979  1.0
  O  O35  1  0.742  0.152  0.021  1.0
  O  O36  1  0.865  0.980  0.351  1.0
[/CIF]
.