MgScNi2SbO6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form MgO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, edges with three equivalent Sc(1)O6 octahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. Sc(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form ScO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Sc(1)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Sc(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-48°. In the second Ni site, Ni(2) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. Sb(1) is bonded in a 3-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Sc(1), one Ni(1), one Ni(2), and one Sb(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Sc(1), one Ni(1), and one Sb(1) atom to form a mixture of distorted corner and edge-sharing OMgScNiSb trigonal pyramids.
MgScNi2SbO6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form MgO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, edges with three equivalent Sc(1)O6 octahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. All Mg(1)-O(1) bond lengths are 2.15 Å. All Mg(1)-O(2) bond lengths are 2.13 Å. Sc(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form ScO6 octahedra that share corners with three equivalent Ni(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. All Sc(1)-O(1) bond lengths are 2.15 Å. All Sc(1)-O(2) bond lengths are 2.13 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Sc(1)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Sc(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-48°. All Ni(1)-O(1) bond lengths are 2.14 Å. All Ni(1)-O(2) bond lengths are 2.21 Å. In the second Ni site, Ni(2) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. All Ni(2)-O(1) bond lengths are 1.92 Å. Sb(1) is bonded in a 3-coordinate geometry to three equivalent O(1) and three equivalent O(2) atoms. All Sb(1)-O(1) bond lengths are 2.66 Å. All Sb(1)-O(2) bond lengths are 2.09 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Sc(1), one Ni(1), one Ni(2), and one Sb(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Sc(1), one Ni(1), and one Sb(1) atom to form a mixture of distorted corner and edge-sharing OMgScNiSb trigonal pyramids.