CaEu2O3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with four equivalent Eu(1)O6 pentagonal pyramids, edges with two equivalent Ca(1)O6 pentagonal pyramids, and edges with ten equivalent Eu(1)O6 pentagonal pyramids. Eu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted EuO6 pentagonal pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with four equivalent Eu(1)O6 pentagonal pyramids, edges with five equivalent Ca(1)O6 pentagonal pyramids, and edges with seven equivalent Eu(1)O6 pentagonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and four equivalent Eu(1) atoms to form a mixture of corner, face, and edge-sharing OCa2Eu4 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the second O site, O(2) is bonded to two equivalent Ca(1) and four equivalent Eu(1) atoms to form a mixture of corner, face, and edge-sharing OCa2Eu4 octahedra. The corner-sharing octahedral tilt angles range from 47-48°.
CaEu2O3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with four equivalent Eu(1)O6 pentagonal pyramids, edges with two equivalent Ca(1)O6 pentagonal pyramids, and edges with ten equivalent Eu(1)O6 pentagonal pyramids. Both Ca(1)-O(2) bond lengths are 2.51 Å. All Ca(1)-O(1) bond lengths are 2.45 Å. Eu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted EuO6 pentagonal pyramids that share corners with two equivalent Ca(1)O6 pentagonal pyramids, corners with four equivalent Eu(1)O6 pentagonal pyramids, edges with five equivalent Ca(1)O6 pentagonal pyramids, and edges with seven equivalent Eu(1)O6 pentagonal pyramids. Both Eu(1)-O(2) bond lengths are 2.50 Å. There are two shorter (2.50 Å) and two longer (2.55 Å) Eu(1)-O(1) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(1) and four equivalent Eu(1) atoms to form a mixture of corner, face, and edge-sharing OCa2Eu4 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the second O site, O(2) is bonded to two equivalent Ca(1) and four equivalent Eu(1) atoms to form a mixture of corner, face, and edge-sharing OCa2Eu4 octahedra. The corner-sharing octahedral tilt angles range from 47-48°.