Eu3TaO6 is (Cubic) Perovskite-like structured and crystallizes in the cubic Fm-3m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to twelve equivalent O(1) atoms to form EuO12 cuboctahedra that share corners with twelve equivalent Eu(1)O12 cuboctahedra, faces with six equivalent Eu(1)O12 cuboctahedra, faces with four equivalent Eu(2)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. In the second Eu site, Eu(2) is bonded to six equivalent O(1) atoms to form EuO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra and faces with eight equivalent Eu(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Ta(1) is bonded to six equivalent O(1) atoms to form TaO6 octahedra that share corners with six equivalent Eu(2)O6 octahedra and faces with eight equivalent Eu(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. O(1) is bonded in a distorted linear geometry to one Eu(2), four equivalent Eu(1), and one Ta(1) atom.
Eu3TaO6 is (Cubic) Perovskite-like structured and crystallizes in the cubic Fm-3m space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to twelve equivalent O(1) atoms to form EuO12 cuboctahedra that share corners with twelve equivalent Eu(1)O12 cuboctahedra, faces with six equivalent Eu(1)O12 cuboctahedra, faces with four equivalent Eu(2)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. All Eu(1)-O(1) bond lengths are 3.01 Å. In the second Eu site, Eu(2) is bonded to six equivalent O(1) atoms to form EuO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra and faces with eight equivalent Eu(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. All Eu(2)-O(1) bond lengths are 2.27 Å. Ta(1) is bonded to six equivalent O(1) atoms to form TaO6 octahedra that share corners with six equivalent Eu(2)O6 octahedra and faces with eight equivalent Eu(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. All Ta(1)-O(1) bond lengths are 1.99 Å. O(1) is bonded in a distorted linear geometry to one Eu(2), four equivalent Eu(1), and one Ta(1) atom.