EuSmHf2O6 crystallizes in the orthorhombic Cmmm space group. Eu(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(3) atoms. Sm(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Hf(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-33°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1), two equivalent Sm(1), and two equivalent Hf(1) atoms to form a mixture of distorted edge and corner-sharing OSm2Eu2Hf2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sm(1) and two equivalent Hf(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1) and two equivalent Hf(1) atoms.
EuSmHf2O6 crystallizes in the orthorhombic Cmmm space group. Eu(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(3) atoms. All Eu(1)-O(1) bond lengths are 2.83 Å. All Eu(1)-O(3) bond lengths are 2.56 Å. Sm(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Sm(1)-O(1) bond lengths are 2.83 Å. All Sm(1)-O(2) bond lengths are 2.52 Å. Hf(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-33°. Both Hf(1)-O(1) bond lengths are 2.10 Å. Both Hf(1)-O(2) bond lengths are 2.11 Å. Both Hf(1)-O(3) bond lengths are 2.07 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1), two equivalent Sm(1), and two equivalent Hf(1) atoms to form a mixture of distorted edge and corner-sharing OSm2Eu2Hf2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sm(1) and two equivalent Hf(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1) and two equivalent Hf(1) atoms.