The compound described by Ta8Cr3O24 crystallizes in the triclinic P1 space group. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(21), one O(22), one O(24), and one O(5) atom to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(8)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-51°. In the second Ta site, Ta(2) is bonded to one O(17), one O(18), one O(2), one O(22), one O(7), and one O(9) atom to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. In the third Ta site, Ta(3) is bonded to one O(12), one O(13), one O(20), one O(21), one O(4), and one O(5) atom to form a mixture of corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 34-58°. In the fourth Ta site, Ta(4) is bonded to one O(11), one O(15), one O(19), one O(20), one O(4), and one O(6) atom to form distorted TaO6 octahedra that share corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra, and  an edgeedge with one Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the fifth Ta site, Ta(5) is bonded to one O(11), one O(12), one O(13), one O(15), one O(16), and one O(8) atom to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(6)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-50°. In the sixth Ta site, Ta(6) is bonded to one O(10), one O(12), one O(13), one O(14), one O(17), and one O(9) atom to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(5)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-58°. In the seventh Ta site, Ta(7) is bonded to one O(16), one O(18), one O(23), one O(3), one O(7), and one O(8) atom to form TaO6 octahedra that share corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. In the eighth Ta site, Ta(8) is bonded to one O(1), one O(20), one O(23), one O(24), one O(3), and one O(4) atom to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(16), one O(17), one O(24), one O(8), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Ta(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the second Cr site, Cr(2) is bonded to one O(19), one O(2), one O(22), one O(23), one O(3), and one O(6) atom to form CrO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-50°. In the third Cr site, Cr(3) is bonded to one O(10), one O(11), one O(14), one O(15), one O(18), and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Ta(5)O6 octahedra, and  an edgeedge with one Ta(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(8), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(7), one Ta(8), and one Cr(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ta(3), one Ta(4), and one Ta(8) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ta(4) and one Cr(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(7), and one Cr(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ta(5), one Ta(7), and one Cr(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(6), and one Cr(1) atom. In the tenth O site, O(10) is bonded in an L-shaped geometry to one Ta(6) and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ta(4), one Ta(5), and one Cr(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ta(3), one Ta(5), and one Ta(6) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ta(3), one Ta(5), and one Ta(6) atom. In the fourteenth O site, O(14) is bonded in an L-shaped geometry to one Ta(6) and one Cr(3) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ta(4), one Ta(5), and one Cr(3) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Ta(5), one Ta(7), and one Cr(1) atom. In the seventeenth O site, O(17) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(6), and one Cr(1) atom. In the eighteenth O site, O(18) is bonded in a trigonal planar geometry to one Ta(2), one Ta(7), and one Cr(3) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one Ta(4) and one Cr(2) atom. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Ta(3), one Ta(4), and one Ta(8) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(3) atom. In the twenty-second O site, O(22) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the twenty-third O site, O(23) is bonded in a distorted trigonal planar geometry to one Ta(7), one Ta(8), and one Cr(2) atom. In the twenty-fourth O site, O(24) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(8), and one Cr(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta8Cr3O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.573
_cell_length_b   6.777
_cell_length_c   9.222
_cell_angle_alpha   89.993
_cell_angle_beta   89.994
_cell_angle_gamma   45.017
_symmetry_Int_Tables_number   1
_cell_volume   423.174
_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
  Ta  Ta0  1  0.001  0.501  0.170  1.0
  Ta  Ta1  1  1.000  0.002  0.331  1.0
  Ta  Ta2  1  0.501  0.998  0.011  1.0
  Ta  Ta3  1  0.501  0.999  0.638  1.0
  Ta  Ta4  1  0.500  0.499  0.829  1.0
  Ta  Ta5  1  0.500  0.499  0.192  1.0
  Ta  Ta6  1  1.000  0.999  0.666  1.0
  Ta  Ta7  1  0.001  0.497  0.836  1.0
  Cr  Cr8  1  0.000  1.000  0.999  1.0
  Cr  Cr9  1  1.000  0.500  0.503  1.0
  Cr  Cr10  1  0.500  0.500  0.499  1.0
  O  O11  1  0.001  0.691  0.998  1.0
  O  O12  1  0.001  0.699  0.331  1.0
  O  O13  1  0.000  0.701  0.672  1.0
  O  O14  1  0.301  0.198  0.835  1.0
  O  O15  1  0.289  0.210  0.146  1.0
  O  O16  1  0.287  0.212  0.517  1.0
  O  O17  1  0.191  0.810  0.500  1.0
  O  O18  1  0.200  0.801  0.826  1.0
  O  O19  1  0.196  0.805  0.171  1.0
  O  O20  1  0.498  0.311  0.334  1.0
  O  O21  1  0.500  0.302  0.674  1.0
  O  O22  1  0.499  0.304  0.995  1.0
  O  O23  1  0.501  0.696  0.995  1.0
  O  O24  1  0.501  0.689  0.333  1.0
  O  O25  1  0.502  0.696  0.674  1.0
  O  O26  1  0.801  0.199  0.827  1.0
  O  O27  1  0.804  0.195  0.172  1.0
  O  O28  1  0.808  0.191  0.500  1.0
  O  O29  1  0.713  0.788  0.515  1.0
  O  O30  1  0.697  0.804  0.835  1.0
  O  O31  1  0.711  0.790  0.146  1.0
  O  O32  1  0.999  0.302  0.330  1.0
  O  O33  1  0.998  0.300  0.672  1.0
  O  O34  1  0.998  0.310  0.998  1.0
[/CIF]
.
The compound described by Ta8Cr3O24 crystallizes in the triclinic P1 space group. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(21), one O(22), one O(24), and one O(5) atom to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(8)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-51°. In the second Ta site, Ta(2) is bonded to one O(17), one O(18), one O(2), one O(22), one O(7), and one O(9) atom to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. In the third Ta site, Ta(3) is bonded to one O(12), one O(13), one O(20), one O(21), one O(4), and one O(5) atom to form a mixture of corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 34-58°. In the fourth Ta site, Ta(4) is bonded to one O(11), one O(15), one O(19), one O(20), one O(4), and one O(6) atom to form distorted TaO6 octahedra that share corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra, and  an edgeedge with one Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the fifth Ta site, Ta(5) is bonded to one O(11), one O(12), one O(13), one O(15), one O(16), and one O(8) atom to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(6)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-50°. In the sixth Ta site, Ta(6) is bonded to one O(10), one O(12), one O(13), one O(14), one O(17), and one O(9) atom to form TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(5)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-58°. In the seventh Ta site, Ta(7) is bonded to one O(16), one O(18), one O(23), one O(3), one O(7), and one O(8) atom to form TaO6 octahedra that share corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cr(3)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. In the eighth Ta site, Ta(8) is bonded to one O(1), one O(20), one O(23), one O(24), one O(3), and one O(4) atom to form TaO6 octahedra that share corners with two equivalent Ta(3)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(16), one O(17), one O(24), one O(8), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra,  an edgeedge with one Ta(2)O6 octahedra, and  an edgeedge with one Ta(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the second Cr site, Cr(2) is bonded to one O(19), one O(2), one O(22), one O(23), one O(3), and one O(6) atom to form CrO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-50°. In the third Cr site, Cr(3) is bonded to one O(10), one O(11), one O(14), one O(15), one O(18), and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Ta(5)O6 octahedra, and  an edgeedge with one Ta(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(8), and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(7), one Ta(8), and one Cr(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ta(3), one Ta(4), and one Ta(8) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ta(4) and one Cr(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(7), and one Cr(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ta(5), one Ta(7), and one Cr(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(6), and one Cr(1) atom. In the tenth O site, O(10) is bonded in an L-shaped geometry to one Ta(6) and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Ta(4), one Ta(5), and one Cr(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ta(3), one Ta(5), and one Ta(6) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Ta(3), one Ta(5), and one Ta(6) atom. In the fourteenth O site, O(14) is bonded in an L-shaped geometry to one Ta(6) and one Cr(3) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ta(4), one Ta(5), and one Cr(3) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Ta(5), one Ta(7), and one Cr(1) atom. In the seventeenth O site, O(17) is bonded in a distorted trigonal planar geometry to one Ta(2), one Ta(6), and one Cr(1) atom. In the eighteenth O site, O(18) is bonded in a trigonal planar geometry to one Ta(2), one Ta(7), and one Cr(3) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one Ta(4) and one Cr(2) atom. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Ta(3), one Ta(4), and one Ta(8) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(3) atom. In the twenty-second O site, O(22) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Cr(2) atom. In the twenty-third O site, O(23) is bonded in a distorted trigonal planar geometry to one Ta(7), one Ta(8), and one Cr(2) atom. In the twenty-fourth O site, O(24) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(8), and one Cr(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta8Cr3O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.573
_cell_length_b   6.777
_cell_length_c   9.222
_cell_angle_alpha   89.993
_cell_angle_beta   89.994
_cell_angle_gamma   45.017
_symmetry_Int_Tables_number   1
_cell_volume   423.174
_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
  Ta  Ta0  1  0.001  0.501  0.170  1.0
  Ta  Ta1  1  1.000  0.002  0.331  1.0
  Ta  Ta2  1  0.501  0.998  0.011  1.0
  Ta  Ta3  1  0.501  0.999  0.638  1.0
  Ta  Ta4  1  0.500  0.499  0.829  1.0
  Ta  Ta5  1  0.500  0.499  0.192  1.0
  Ta  Ta6  1  1.000  0.999  0.666  1.0
  Ta  Ta7  1  0.001  0.497  0.836  1.0
  Cr  Cr8  1  0.000  1.000  0.999  1.0
  Cr  Cr9  1  1.000  0.500  0.503  1.0
  Cr  Cr10  1  0.500  0.500  0.499  1.0
  O  O11  1  0.001  0.691  0.998  1.0
  O  O12  1  0.001  0.699  0.331  1.0
  O  O13  1  0.000  0.701  0.672  1.0
  O  O14  1  0.301  0.198  0.835  1.0
  O  O15  1  0.289  0.210  0.146  1.0
  O  O16  1  0.287  0.212  0.517  1.0
  O  O17  1  0.191  0.810  0.500  1.0
  O  O18  1  0.200  0.801  0.826  1.0
  O  O19  1  0.196  0.805  0.171  1.0
  O  O20  1  0.498  0.311  0.334  1.0
  O  O21  1  0.500  0.302  0.674  1.0
  O  O22  1  0.499  0.304  0.995  1.0
  O  O23  1  0.501  0.696  0.995  1.0
  O  O24  1  0.501  0.689  0.333  1.0
  O  O25  1  0.502  0.696  0.674  1.0
  O  O26  1  0.801  0.199  0.827  1.0
  O  O27  1  0.804  0.195  0.172  1.0
  O  O28  1  0.808  0.191  0.500  1.0
  O  O29  1  0.713  0.788  0.515  1.0
  O  O30  1  0.697  0.804  0.835  1.0
  O  O31  1  0.711  0.790  0.146  1.0
  O  O32  1  0.999  0.302  0.330  1.0
  O  O33  1  0.998  0.300  0.672  1.0
  O  O34  1  0.998  0.310  0.998  1.0
[/CIF]
.