The material described by Ca2Ta2CoO8 crystallizes in the triclinic P1 space group. There are eight inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(17), one O(20), one O(21), one O(23), one O(28), one O(29), one O(31), and one O(5) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(18), one O(19), one O(22), one O(24), one O(27), one O(30), one O(32), and one O(6) atom. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(17), one O(20), one O(21), one O(23), one O(25), one O(29), one O(31), and one O(7) atom. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(18), one O(19), one O(22), one O(24), one O(26), one O(30), one O(32), and one O(8) atom. In the fifth Ca site, Ca(5) is bonded in a 8-coordinate geometry to one O(1), one O(17), one O(19), one O(22), one O(23), one O(25), one O(27), and one O(32) atom. In the sixth Ca site, Ca(6) is bonded in a 8-coordinate geometry to one O(18), one O(2), one O(20), one O(21), one O(24), one O(26), one O(28), and one O(31) atom. In the seventh Ca site, Ca(7) is bonded in a 8-coordinate geometry to one O(17), one O(19), one O(22), one O(23), one O(25), one O(27), one O(29), and one O(3) atom. In the eighth Ca site, Ca(8) is bonded in a 8-coordinate geometry to one O(18), one O(20), one O(21), one O(24), one O(26), one O(28), one O(30), and one O(4) atom. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(17), one O(2), one O(21), one O(31), one O(7), and one O(9) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(1)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Ta site, Ta(2) is bonded to one O(1), one O(10), one O(18), one O(22), one O(32), and one O(8) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the third Ta site, Ta(3) is bonded to one O(11), one O(20), one O(23), one O(29), one O(3), and one O(5) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(3)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 45-55°. In the fourth Ta site, Ta(4) is bonded to one O(12), one O(19), one O(24), one O(30), one O(4), and one O(6) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(1)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 44-55°. In the fifth Ta site, Ta(5) is bonded to one O(13), one O(19), one O(23), one O(27), one O(3), and one O(6) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra, and  an edgeedge with one Ta(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the sixth Ta site, Ta(6) is bonded to one O(14), one O(20), one O(24), one O(28), one O(4), and one O(5) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra, and  an edgeedge with one Ta(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the seventh Ta site, Ta(7) is bonded to one O(1), one O(15), one O(17), one O(22), one O(25), and one O(7) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the eighth Ta site, Ta(8) is bonded to one O(16), one O(18), one O(2), one O(21), one O(26), and one O(8) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(12), one O(14), one O(16), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Ta(5)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra,  a cornercorner with one Ta(7)O6 octahedra,  a cornercorner with one Ta(8)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, and  an edgeedge with one Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Co site, Co(2) is bonded to one O(10), one O(12), one O(13), one O(16), one O(2), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra, corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the third Co site, Co(3) is bonded to one O(10), one O(11), one O(13), one O(15), one O(5), and one O(8) atom to form CoO6 octahedra that share  a cornercorner with one Ta(5)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra,  a cornercorner with one Ta(7)O6 octahedra,  a cornercorner with one Ta(8)O6 octahedra, corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, and  an edgeedge with one Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the fourth Co site, Co(4) is bonded to one O(1), one O(11), one O(14), one O(15), one O(4), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are thirty-two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(5), one Ta(2), one Ta(7), and one Co(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(6), one Ta(1), one Ta(8), and one Co(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(7), one Ta(3), one Ta(5), and one Co(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(8), one Ta(4), one Ta(6), and one Co(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ta(3), one Ta(6), and one Co(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ta(4), one Ta(5), and one Co(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ta(1), one Ta(7), and one Co(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(4), one Ta(2), one Ta(8), and one Co(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ta(1), one Co(1), and one Co(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ta(2), one Co(2), and one Co(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ta(3), one Co(3), and one Co(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ta(4), one Co(1), and one Co(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Ta(5), one Co(2), and one Co(3) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ta(6), one Co(1), and one Co(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Ta(7), one Co(3), and one Co(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ta(8), one Co(1), and one Co(2) atom. In the seventeenth O site, O(17) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(5), one Ca(7), one Ta(1), and one Ta(7) atom. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(6), one Ca(8), one Ta(2), and one Ta(8) atom. In the nineteenth O site, O(19) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Ca(7), one Ta(4), and one Ta(5) atom. In the twentieth O site, O(20) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(6), one Ca(8), one Ta(3), and one Ta(6) atom. In the twenty-first O site, O(21) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(6), one Ca(8), one Ta(1), and one Ta(8) atom. In the twenty-second O site, O(22) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Ca(7), one Ta(2), and one Ta(7) atom. In the twenty-third O site, O(23) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(5), one Ca(7), one Ta(3), and one Ta(5) atom. In the twenty-fourth O site, O(24) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(6), one Ca(8), one Ta(4), and one Ta(6) atom. In the twenty-fifth O site, O(25) is bonded to one Ca(3), one Ca(5), one Ca(7), and one Ta(7) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-sixth O site, O(26) is bonded to one Ca(4), one Ca(6), one Ca(8), and one Ta(8) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-seventh O site, O(27) is bonded to one Ca(2), one Ca(5), one Ca(7), and one Ta(5) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-eighth O site, O(28) is bonded to one Ca(1), one Ca(6), one Ca(8), and one Ta(6) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-ninth O site, O(29) is bonded to one Ca(1), one Ca(3), one Ca(7), and one Ta(3) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirtieth O site, O(30) is bonded to one Ca(2), one Ca(4), one Ca(8), and one Ta(4) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirty-first O site, O(31) is bonded to one Ca(1), one Ca(3), one Ca(6), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirty-second O site, O(32) is bonded to one Ca(2), one Ca(4), one Ca(5), and one Ta(2) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. is represented by the CIF card [CIF]
data_Ca2Ta2CoO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.465
_cell_length_b   6.346
_cell_length_c   10.006
_cell_angle_alpha   108.441
_cell_angle_beta   91.766
_cell_angle_gamma   90.077
_symmetry_Int_Tables_number   1
_cell_volume   329.014
_cell_formula_units_Z   2
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  0.756  0.470  0.585  1.0
  Ca  Ca1  1  0.740  0.885  0.415  1.0
  Ca  Ca2  1  0.241  0.529  0.417  1.0
  Ca  Ca3  1  0.255  0.112  0.584  1.0
  Co  Co4  1  0.748  0.637  0.001  1.0
  Co  Co5  1  0.247  0.361  1.000  1.0
  O  O6  1  0.086  0.196  0.140  1.0
  O  O7  1  0.412  0.054  0.861  1.0
  O  O8  1  0.910  0.802  0.860  1.0
  O  O9  1  0.586  0.943  0.141  1.0
  O  O10  1  0.581  0.408  0.113  1.0
  O  O11  1  0.916  0.294  0.887  1.0
  O  O12  1  0.415  0.590  0.888  1.0
  O  O13  1  0.079  0.705  0.113  1.0
  O  O14  1  0.495  0.241  0.362  1.0
  O  O15  1  0.002  0.878  0.638  1.0
  O  O16  1  0.995  0.120  0.363  1.0
  O  O17  1  0.501  0.757  0.639  1.0
  O  O18  1  0.338  0.836  0.370  1.0
  O  O19  1  0.158  0.467  0.631  1.0
  O  O20  1  0.657  0.160  0.630  1.0
  O  O21  1  0.839  0.531  0.370  1.0
  Ta  Ta22  1  0.750  0.260  0.223  1.0
  Ta  Ta23  1  0.746  0.036  0.777  1.0
  Ta  Ta24  1  0.246  0.738  0.778  1.0
  Ta  Ta25  1  0.250  0.961  0.223  1.0
[/CIF]
.
The material described by Ca2Ta2CoO8 crystallizes in the triclinic P1 space group. There are eight inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(17), one O(20), one O(21), one O(23), one O(28), one O(29), one O(31), and one O(5) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(18), one O(19), one O(22), one O(24), one O(27), one O(30), one O(32), and one O(6) atom. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(17), one O(20), one O(21), one O(23), one O(25), one O(29), one O(31), and one O(7) atom. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(18), one O(19), one O(22), one O(24), one O(26), one O(30), one O(32), and one O(8) atom. In the fifth Ca site, Ca(5) is bonded in a 8-coordinate geometry to one O(1), one O(17), one O(19), one O(22), one O(23), one O(25), one O(27), and one O(32) atom. In the sixth Ca site, Ca(6) is bonded in a 8-coordinate geometry to one O(18), one O(2), one O(20), one O(21), one O(24), one O(26), one O(28), and one O(31) atom. In the seventh Ca site, Ca(7) is bonded in a 8-coordinate geometry to one O(17), one O(19), one O(22), one O(23), one O(25), one O(27), one O(29), and one O(3) atom. In the eighth Ca site, Ca(8) is bonded in a 8-coordinate geometry to one O(18), one O(20), one O(21), one O(24), one O(26), one O(28), one O(30), and one O(4) atom. There are eight inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(17), one O(2), one O(21), one O(31), one O(7), and one O(9) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(1)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Ta site, Ta(2) is bonded to one O(1), one O(10), one O(18), one O(22), one O(32), and one O(8) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Ta(7)O6 octahedra, and  an edgeedge with one Ta(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the third Ta site, Ta(3) is bonded to one O(11), one O(20), one O(23), one O(29), one O(3), and one O(5) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(3)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 45-55°. In the fourth Ta site, Ta(4) is bonded to one O(12), one O(19), one O(24), one O(30), one O(4), and one O(6) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra, corners with two equivalent Co(1)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 44-55°. In the fifth Ta site, Ta(5) is bonded to one O(13), one O(19), one O(23), one O(27), one O(3), and one O(6) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra, and  an edgeedge with one Ta(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the sixth Ta site, Ta(6) is bonded to one O(14), one O(20), one O(24), one O(28), one O(4), and one O(5) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra,  an edgeedge with one Ta(3)O6 octahedra, and  an edgeedge with one Ta(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the seventh Ta site, Ta(7) is bonded to one O(1), one O(15), one O(17), one O(22), one O(25), and one O(7) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(4)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the eighth Ta site, Ta(8) is bonded to one O(16), one O(18), one O(2), one O(21), one O(26), and one O(8) atom to form distorted TaO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra,  an edgeedge with one Ta(1)O6 octahedra, and  an edgeedge with one Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(12), one O(14), one O(16), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Ta(5)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra,  a cornercorner with one Ta(7)O6 octahedra,  a cornercorner with one Ta(8)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, and  an edgeedge with one Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. In the second Co site, Co(2) is bonded to one O(10), one O(12), one O(13), one O(16), one O(2), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra, corners with two equivalent Ta(5)O6 octahedra, corners with two equivalent Ta(8)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the third Co site, Co(3) is bonded to one O(10), one O(11), one O(13), one O(15), one O(5), and one O(8) atom to form CoO6 octahedra that share  a cornercorner with one Ta(5)O6 octahedra,  a cornercorner with one Ta(6)O6 octahedra,  a cornercorner with one Ta(7)O6 octahedra,  a cornercorner with one Ta(8)O6 octahedra, corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, and  an edgeedge with one Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the fourth Co site, Co(4) is bonded to one O(1), one O(11), one O(14), one O(15), one O(4), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra,  a cornercorner with one Ta(2)O6 octahedra,  a cornercorner with one Ta(3)O6 octahedra,  a cornercorner with one Ta(4)O6 octahedra, corners with two equivalent Ta(6)O6 octahedra, corners with two equivalent Ta(7)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are thirty-two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(5), one Ta(2), one Ta(7), and one Co(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(6), one Ta(1), one Ta(8), and one Co(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(7), one Ta(3), one Ta(5), and one Co(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(8), one Ta(4), one Ta(6), and one Co(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ta(3), one Ta(6), and one Co(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ta(4), one Ta(5), and one Co(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ta(1), one Ta(7), and one Co(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ca(4), one Ta(2), one Ta(8), and one Co(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ta(1), one Co(1), and one Co(4) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ta(2), one Co(2), and one Co(3) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ta(3), one Co(3), and one Co(4) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ta(4), one Co(1), and one Co(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Ta(5), one Co(2), and one Co(3) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Ta(6), one Co(1), and one Co(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Ta(7), one Co(3), and one Co(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ta(8), one Co(1), and one Co(2) atom. In the seventeenth O site, O(17) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(5), one Ca(7), one Ta(1), and one Ta(7) atom. In the eighteenth O site, O(18) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(6), one Ca(8), one Ta(2), and one Ta(8) atom. In the nineteenth O site, O(19) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Ca(7), one Ta(4), and one Ta(5) atom. In the twentieth O site, O(20) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(6), one Ca(8), one Ta(3), and one Ta(6) atom. In the twenty-first O site, O(21) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(6), one Ca(8), one Ta(1), and one Ta(8) atom. In the twenty-second O site, O(22) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(5), one Ca(7), one Ta(2), and one Ta(7) atom. In the twenty-third O site, O(23) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(3), one Ca(5), one Ca(7), one Ta(3), and one Ta(5) atom. In the twenty-fourth O site, O(24) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(4), one Ca(6), one Ca(8), one Ta(4), and one Ta(6) atom. In the twenty-fifth O site, O(25) is bonded to one Ca(3), one Ca(5), one Ca(7), and one Ta(7) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-sixth O site, O(26) is bonded to one Ca(4), one Ca(6), one Ca(8), and one Ta(8) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-seventh O site, O(27) is bonded to one Ca(2), one Ca(5), one Ca(7), and one Ta(5) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-eighth O site, O(28) is bonded to one Ca(1), one Ca(6), one Ca(8), and one Ta(6) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the twenty-ninth O site, O(29) is bonded to one Ca(1), one Ca(3), one Ca(7), and one Ta(3) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirtieth O site, O(30) is bonded to one Ca(2), one Ca(4), one Ca(8), and one Ta(4) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirty-first O site, O(31) is bonded to one Ca(1), one Ca(3), one Ca(6), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. In the thirty-second O site, O(32) is bonded to one Ca(2), one Ca(4), one Ca(5), and one Ta(2) atom to form a mixture of distorted corner and edge-sharing OCa3Ta trigonal pyramids. is represented by the CIF card [CIF]
data_Ca2Ta2CoO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.465
_cell_length_b   6.346
_cell_length_c   10.006
_cell_angle_alpha   108.441
_cell_angle_beta   91.766
_cell_angle_gamma   90.077
_symmetry_Int_Tables_number   1
_cell_volume   329.014
_cell_formula_units_Z   2
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  0.756  0.470  0.585  1.0
  Ca  Ca1  1  0.740  0.885  0.415  1.0
  Ca  Ca2  1  0.241  0.529  0.417  1.0
  Ca  Ca3  1  0.255  0.112  0.584  1.0
  Co  Co4  1  0.748  0.637  0.001  1.0
  Co  Co5  1  0.247  0.361  1.000  1.0
  O  O6  1  0.086  0.196  0.140  1.0
  O  O7  1  0.412  0.054  0.861  1.0
  O  O8  1  0.910  0.802  0.860  1.0
  O  O9  1  0.586  0.943  0.141  1.0
  O  O10  1  0.581  0.408  0.113  1.0
  O  O11  1  0.916  0.294  0.887  1.0
  O  O12  1  0.415  0.590  0.888  1.0
  O  O13  1  0.079  0.705  0.113  1.0
  O  O14  1  0.495  0.241  0.362  1.0
  O  O15  1  0.002  0.878  0.638  1.0
  O  O16  1  0.995  0.120  0.363  1.0
  O  O17  1  0.501  0.757  0.639  1.0
  O  O18  1  0.338  0.836  0.370  1.0
  O  O19  1  0.158  0.467  0.631  1.0
  O  O20  1  0.657  0.160  0.630  1.0
  O  O21  1  0.839  0.531  0.370  1.0
  Ta  Ta22  1  0.750  0.260  0.223  1.0
  Ta  Ta23  1  0.746  0.036  0.777  1.0
  Ta  Ta24  1  0.246  0.738  0.778  1.0
  Ta  Ta25  1  0.250  0.961  0.223  1.0
[/CIF]
.