KEuNb2O6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pmn2_1 space group. K(1) is bonded to two equivalent O(1), two equivalent O(2), four equivalent O(3), and four equivalent O(4) atoms to form distorted KO12 cuboctahedra that share corners with twelve equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(4), and four equivalent O(3) atoms. Nb(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with four equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-21°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), two equivalent Eu(1), and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms.
KEuNb2O6 is Orthorhombic Perovskite-derived structured and crystallizes in the orthorhombic Pmn2_1 space group. K(1) is bonded to two equivalent O(1), two equivalent O(2), four equivalent O(3), and four equivalent O(4) atoms to form distorted KO12 cuboctahedra that share corners with twelve equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. There is one shorter (2.78 Å) and one longer (3.04 Å) K(1)-O(1) bond length. There is one shorter (2.68 Å) and one longer (3.03 Å) K(1)-O(2) bond length. There are two shorter (2.71 Å) and two longer (3.15 Å) K(1)-O(3) bond lengths. There are two shorter (2.83 Å) and two longer (2.85 Å) K(1)-O(4) bond lengths. Eu(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), two equivalent O(4), and four equivalent O(3) atoms. The Eu(1)-O(1) bond length is 2.60 Å. The Eu(1)-O(2) bond length is 2.62 Å. Both Eu(1)-O(4) bond lengths are 2.61 Å. There are two shorter (2.73 Å) and two longer (2.80 Å) Eu(1)-O(3) bond lengths. Nb(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with four equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-21°. The Nb(1)-O(1) bond length is 2.04 Å. The Nb(1)-O(2) bond length is 2.05 Å. There is one shorter (2.05 Å) and one longer (2.06 Å) Nb(1)-O(3) bond length. There is one shorter (2.05 Å) and one longer (2.06 Å) Nb(1)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent K(1), two equivalent Eu(1), and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Eu(1), and two equivalent Nb(1) atoms.