Sr2MgHfCrO6 crystallizes in the orthorhombic Immm space group. Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Hf(1) is bonded in an octahedral geometry to two equivalent O(1) and four equivalent O(2) atoms. Cr(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and one Hf(1) atom to form distorted OSr4Hf trigonal bipyramids that share corners with five equivalent O(1)Sr4Hf trigonal bipyramids, corners with twelve equivalent O(2)Sr2HfMgCr trigonal bipyramids, edges with four equivalent O(2)Sr2HfMgCr trigonal bipyramids, and edges with four equivalent O(1)Sr4Hf trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Sr(1), one Mg(1), one Hf(1), and one Cr(1) atom to form distorted OSr2HfMgCr trigonal bipyramids that share corners with three equivalent O(2)Sr2HfMgCr trigonal bipyramids, corners with six equivalent O(1)Sr4Hf trigonal bipyramids, edges with two equivalent O(1)Sr4Hf trigonal bipyramids, edges with three equivalent O(2)Sr2HfMgCr trigonal bipyramids, and faces with two equivalent O(2)Sr2HfMgCr trigonal bipyramids.
Sr2MgHfCrO6 crystallizes in the orthorhombic Immm space group. Sr(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. There are two shorter (2.85 Å) and two longer (3.13 Å) Sr(1)-O(1) bond lengths. All Sr(1)-O(2) bond lengths are 2.75 Å. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Mg(1)-O(2) bond lengths are 2.01 Å. Hf(1) is bonded in an octahedral geometry to two equivalent O(1) and four equivalent O(2) atoms. Both Hf(1)-O(1) bond lengths are 2.10 Å. All Hf(1)-O(2) bond lengths are 2.06 Å. Cr(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Cr(1)-O(2) bond lengths are 1.98 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and one Hf(1) atom to form distorted OSr4Hf trigonal bipyramids that share corners with five equivalent O(1)Sr4Hf trigonal bipyramids, corners with twelve equivalent O(2)Sr2HfMgCr trigonal bipyramids, edges with four equivalent O(2)Sr2HfMgCr trigonal bipyramids, and edges with four equivalent O(1)Sr4Hf trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Sr(1), one Mg(1), one Hf(1), and one Cr(1) atom to form distorted OSr2HfMgCr trigonal bipyramids that share corners with three equivalent O(2)Sr2HfMgCr trigonal bipyramids, corners with six equivalent O(1)Sr4Hf trigonal bipyramids, edges with two equivalent O(1)Sr4Hf trigonal bipyramids, edges with three equivalent O(2)Sr2HfMgCr trigonal bipyramids, and faces with two equivalent O(2)Sr2HfMgCr trigonal bipyramids.