Nb7(Ru3B4)2 crystallizes in the hexagonal P6/m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to twelve equivalent B(2) atoms to form face-sharing NbB12 cuboctahedra. In the second Nb site, Nb(2) is bonded in a 11-coordinate geometry to six equivalent Ru(1), one B(1), and four equivalent B(2) atoms. Ru(1) is bonded in a 9-coordinate geometry to six equivalent Nb(2), one B(2), and two equivalent B(1) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to three equivalent Nb(2) and six equivalent Ru(1) atoms. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nb(1), four equivalent Nb(2), one Ru(1), and two equivalent B(2) atoms.
Nb7(Ru3B4)2 crystallizes in the hexagonal P6/m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to twelve equivalent B(2) atoms to form face-sharing NbB12 cuboctahedra. All Nb(1)-B(2) bond lengths are 2.44 Å. In the second Nb site, Nb(2) is bonded in a 11-coordinate geometry to six equivalent Ru(1), one B(1), and four equivalent B(2) atoms. There are four shorter (2.78 Å) and two longer (2.88 Å) Nb(2)-Ru(1) bond lengths. The Nb(2)-B(1) bond length is 2.71 Å. All Nb(2)-B(2) bond lengths are 2.38 Å. Ru(1) is bonded in a 9-coordinate geometry to six equivalent Nb(2), one B(2), and two equivalent B(1) atoms. The Ru(1)-B(2) bond length is 2.54 Å. Both Ru(1)-B(1) bond lengths are 2.24 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to three equivalent Nb(2) and six equivalent Ru(1) atoms. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nb(1), four equivalent Nb(2), one Ru(1), and two equivalent B(2) atoms. Both B(2)-B(2) bond lengths are 1.87 Å.