Ta5B6 crystallizes in the orthorhombic Cmmm space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 7-coordinate geometry to one B(3) and six equivalent B(2) atoms. In the second Ta site, Ta(2) is bonded in a 7-coordinate geometry to one B(2), two equivalent B(1), and four equivalent B(3) atoms. In the third Ta site, Ta(3) is bonded to four equivalent B(3) and eight equivalent B(1) atoms to form a mixture of edge and face-sharing TaB12 cuboctahedra. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Ta(2), four equivalent Ta(3), one B(1), and two equivalent B(3) atoms. In the second B site, B(2) is bonded in a 9-coordinate geometry to one Ta(2), six equivalent Ta(1), and two equivalent B(2) atoms. In the third B site, B(3) is bonded in a 9-coordinate geometry to one Ta(1), two equivalent Ta(3), four equivalent Ta(2), and two equivalent B(1) atoms.
Ta5B6 crystallizes in the orthorhombic Cmmm space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 7-coordinate geometry to one B(3) and six equivalent B(2) atoms. The Ta(1)-B(3) bond length is 2.54 Å. There are four shorter (2.39 Å) and two longer (2.43 Å) Ta(1)-B(2) bond lengths. In the second Ta site, Ta(2) is bonded in a 7-coordinate geometry to one B(2), two equivalent B(1), and four equivalent B(3) atoms. The Ta(2)-B(2) bond length is 2.55 Å. Both Ta(2)-B(1) bond lengths are 2.36 Å. All Ta(2)-B(3) bond lengths are 2.39 Å. In the third Ta site, Ta(3) is bonded to four equivalent B(3) and eight equivalent B(1) atoms to form a mixture of edge and face-sharing TaB12 cuboctahedra. All Ta(3)-B(3) bond lengths are 2.49 Å. All Ta(3)-B(1) bond lengths are 2.45 Å. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Ta(2), four equivalent Ta(3), one B(1), and two equivalent B(3) atoms. The B(1)-B(1) bond length is 1.80 Å. Both B(1)-B(3) bond lengths are 1.85 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to one Ta(2), six equivalent Ta(1), and two equivalent B(2) atoms. Both B(2)-B(2) bond lengths are 1.90 Å. In the third B site, B(3) is bonded in a 9-coordinate geometry to one Ta(1), two equivalent Ta(3), four equivalent Ta(2), and two equivalent B(1) atoms.