KCaTbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pnnn space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second K site, K(2) is bonded in a 12-coordinate geometry to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form CaO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Tb(1), and one Nb(1) atom.
KCaTbNbO6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pnnn space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All K(1)-O(1) bond lengths are 2.97 Å. All K(1)-O(2) bond lengths are 2.71 Å. In the second K site, K(2) is bonded in a 12-coordinate geometry to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. All K(2)-O(1) bond lengths are 2.70 Å. All K(2)-O(2) bond lengths are 3.24 Å. All K(2)-O(3) bond lengths are 3.12 Å. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Ca(1)-O(3) bond lengths are 2.48 Å. In the second Ca site, Ca(2) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form CaO12 cuboctahedra that share faces with four equivalent Tb(1)O6 octahedra and faces with four equivalent Nb(1)O6 octahedra. All Ca(2)-O(1) bond lengths are 3.00 Å. All Ca(2)-O(2) bond lengths are 2.84 Å. All Ca(2)-O(3) bond lengths are 2.91 Å. Tb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. Both Tb(1)-O(1) bond lengths are 2.25 Å. Both Tb(1)-O(2) bond lengths are 2.25 Å. Both Tb(1)-O(3) bond lengths are 2.27 Å. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with six equivalent Tb(1)O6 octahedra and faces with two equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 15-28°. Both Nb(1)-O(1) bond lengths are 1.99 Å. Both Nb(1)-O(2) bond lengths are 2.00 Å. Both Nb(1)-O(3) bond lengths are 2.04 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ca(2), one Tb(1), and one Nb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(2), one Ca(1), one Ca(2), one Tb(1), and one Nb(1) atom.