RuNi4 crystallizes in the trigonal R-3m space group. Ru(1) is bonded to six equivalent Ru(1) and six equivalent Ni(1) atoms to form RuNi6Ru6 cuboctahedra that share corners with six equivalent Ru(1)Ni6Ru6 cuboctahedra, corners with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Ru(1)Ni6Ru6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with twelve equivalent Ni(1)Ni9Ru3 cuboctahedra, faces with six equivalent Ru(1)Ni6Ru6 cuboctahedra, and faces with twelve equivalent Ni(1)Ni9Ru3 cuboctahedra. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ru(1), three equivalent Ni(2), and six equivalent Ni(1) atoms to form NiNi9Ru3 cuboctahedra that share corners with three equivalent Ni(2)Ni12 cuboctahedra; corners with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with six equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine Ni(2,2)Ni12 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; faces with six equivalent Ru(1)Ni6Ru6 cuboctahedra; faces with six equivalent Ni(2)Ni12 cuboctahedra; and faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra. In the second Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra. In the third Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra. In the fourth Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra.
RuNi4 crystallizes in the trigonal R-3m space group. Ru(1) is bonded to six equivalent Ru(1) and six equivalent Ni(1) atoms to form RuNi6Ru6 cuboctahedra that share corners with six equivalent Ru(1)Ni6Ru6 cuboctahedra, corners with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Ru(1)Ni6Ru6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with twelve equivalent Ni(1)Ni9Ru3 cuboctahedra, faces with six equivalent Ru(1)Ni6Ru6 cuboctahedra, and faces with twelve equivalent Ni(1)Ni9Ru3 cuboctahedra. All Ru(1)-Ru(1) bond lengths are 2.56 Å. All Ru(1)-Ni(1) bond lengths are 2.55 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ru(1), three equivalent Ni(2), and six equivalent Ni(1) atoms to form NiNi9Ru3 cuboctahedra that share corners with three equivalent Ni(2)Ni12 cuboctahedra; corners with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with six equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine Ni(2,2)Ni12 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; faces with six equivalent Ru(1)Ni6Ru6 cuboctahedra; faces with six equivalent Ni(2)Ni12 cuboctahedra; and faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.48 Å. All Ni(1)-Ni(1) bond lengths are 2.56 Å. In the second Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra. There are three shorter (2.48 Å) and six longer (2.56 Å) Ni(2)-Ni(2,2) bond lengths. In the third Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra. All Ni(2)-Ni(1) bond lengths are 2.48 Å. All Ni(2)-Ni(2) bond lengths are 2.56 Å. In the fourth Ni site, Ni(2) is bonded to three equivalent Ni(1) and nine Ni(2,2) atoms to form NiNi12 cuboctahedra that share corners with three equivalent Ru(1)Ni6Ru6 cuboctahedra; corners with three equivalent Ni(1)Ni9Ru3 cuboctahedra; corners with six equivalent Ni(2)Ni12 cuboctahedra; edges with three equivalent Ru(1)Ni6Ru6 cuboctahedra; edges with nine equivalent Ni(1)Ni9Ru3 cuboctahedra; edges with twelve Ni(2,2)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ni9Ru3 cuboctahedra; and faces with twelve Ni(2,2)Ni12 cuboctahedra. All Ni(2)-Ni(1) bond lengths are 2.48 Å. There are three shorter (2.48 Å) and six longer (2.56 Å) Ni(2)-Ni(2,2) bond lengths.