Sr4Hf3O10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to four equivalent O(4) and five equivalent O(2) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-24°. In the second Hf site, Hf(2) is bonded to one O(1), one O(2), and four equivalent O(4) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-22°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Hf(1) atoms. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(2), and two equivalent Hf(2) atoms. In the third O site, O(1) is bonded in a distorted linear geometry to four equivalent Sr(1), one Hf(1), and one Hf(2) atom. In the fourth O site, O(2) is bonded to five equivalent Sr(2) and one Hf(2) atom to form a mixture of distorted corner and edge-sharing OSr5Hf octahedra. The corner-sharing octahedral tilt angles are 7°.
Sr4Hf3O10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(1) atoms. Both Sr(1)-O(3) bond lengths are 2.60 Å. Both Sr(1)-O(4) bond lengths are 2.64 Å. All Sr(1)-O(1) bond lengths are 2.86 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to four equivalent O(4) and five equivalent O(2) atoms. There are two shorter (2.54 Å) and two longer (3.09 Å) Sr(2)-O(4) bond lengths. There is one shorter (2.46 Å) and four longer (2.87 Å) Sr(2)-O(2) bond lengths. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-24°. Both Hf(1)-O(1) bond lengths are 2.07 Å. All Hf(1)-O(3) bond lengths are 2.07 Å. In the second Hf site, Hf(2) is bonded to one O(1), one O(2), and four equivalent O(4) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles range from 0-22°. The Hf(2)-O(1) bond length is 2.09 Å. The Hf(2)-O(2) bond length is 2.07 Å. All Hf(2)-O(4) bond lengths are 2.06 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Hf(1) atoms. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(2), and two equivalent Hf(2) atoms. In the third O site, O(1) is bonded in a distorted linear geometry to four equivalent Sr(1), one Hf(1), and one Hf(2) atom. In the fourth O site, O(2) is bonded to five equivalent Sr(2) and one Hf(2) atom to form a mixture of distorted corner and edge-sharing OSr5Hf octahedra. The corner-sharing octahedral tilt angles are 7°.