Ca2HfO4 crystallizes in the orthorhombic Pbca space group. Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. Hf(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and one Hf(1) atom to form corner-sharing OCa3Hf tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Hf(1) atoms.
Ca2HfO4 crystallizes in the orthorhombic Pbca space group. Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. There are a spread of Ca(1)-O(1) bond distances ranging from 2.28-2.42 Å. There are a spread of Ca(1)-O(2) bond distances ranging from 2.38-2.81 Å. Hf(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 32°. Both Hf(1)-O(1) bond lengths are 2.09 Å. There are two shorter (2.10 Å) and two longer (2.11 Å) Hf(1)-O(2) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and one Hf(1) atom to form corner-sharing OCa3Hf tetrahedra. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Hf(1) atoms.