ScNiC2 crystallizes in the tetragonal P4/nmm space group. Sc(1) is bonded to five equivalent C(2) atoms to form a mixture of distorted corner and edge-sharing ScC5 square pyramids. Ni(1) is bonded to four equivalent C(1) atoms to form NiC4 tetrahedra that share corners with four equivalent C(2)Sc5C octahedra, corners with four equivalent Ni(1)C4 tetrahedra, and edges with four equivalent Ni(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 5-coordinate geometry to four equivalent Ni(1) and one C(2) atom. In the second C site, C(2) is bonded to five equivalent Sc(1) and one C(1) atom to form CSc5C octahedra that share corners with four equivalent C(2)Sc5C octahedra, corners with four equivalent Ni(1)C4 tetrahedra, and edges with eight equivalent C(2)Sc5C octahedra. The corner-sharing octahedral tilt angles are 4°.
ScNiC2 crystallizes in the tetragonal P4/nmm space group. Sc(1) is bonded to five equivalent C(2) atoms to form a mixture of distorted corner and edge-sharing ScC5 square pyramids. There is one shorter (2.20 Å) and four longer (2.39 Å) Sc(1)-C(2) bond lengths. Ni(1) is bonded to four equivalent C(1) atoms to form NiC4 tetrahedra that share corners with four equivalent C(2)Sc5C octahedra, corners with four equivalent Ni(1)C4 tetrahedra, and edges with four equivalent Ni(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. All Ni(1)-C(1) bond lengths are 2.06 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 5-coordinate geometry to four equivalent Ni(1) and one C(2) atom. The C(1)-C(2) bond length is 1.37 Å. In the second C site, C(2) is bonded to five equivalent Sc(1) and one C(1) atom to form CSc5C octahedra that share corners with four equivalent C(2)Sc5C octahedra, corners with four equivalent Ni(1)C4 tetrahedra, and edges with eight equivalent C(2)Sc5C octahedra. The corner-sharing octahedral tilt angles are 4°.