Nb3W3B4 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 10-coordinate geometry to two equivalent W(1), four equivalent W(2), one B(1), one B(2), and two equivalent B(3) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent B(2) and four equivalent B(3) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 10-coordinate geometry to four equivalent Nb(1), two equivalent B(1), and four equivalent B(3) atoms. In the second W site, W(2) is bonded in a 10-coordinate geometry to four equivalent Nb(1), two equivalent B(1), two equivalent B(2), and two equivalent B(3) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent W(1), four equivalent W(2), and one B(2) atom. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), four equivalent W(2), and one B(1) atom. In the third B site, B(3) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent W(1), two equivalent W(2), and one B(3) atom.
Nb3W3B4 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 10-coordinate geometry to two equivalent W(1), four equivalent W(2), one B(1), one B(2), and two equivalent B(3) atoms. Both Nb(1)-W(1) bond lengths are 2.77 Å. There are two shorter (2.80 Å) and two longer (2.81 Å) Nb(1)-W(2) bond lengths. The Nb(1)-B(1) bond length is 2.49 Å. The Nb(1)-B(2) bond length is 2.51 Å. There is one shorter (2.47 Å) and one longer (2.52 Å) Nb(1)-B(3) bond length. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent B(2) and four equivalent B(3) atoms. Both Nb(2)-B(2) bond lengths are 2.50 Å. All Nb(2)-B(3) bond lengths are 2.44 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 10-coordinate geometry to four equivalent Nb(1), two equivalent B(1), and four equivalent B(3) atoms. Both W(1)-B(1) bond lengths are 2.49 Å. All W(1)-B(3) bond lengths are 2.41 Å. In the second W site, W(2) is bonded in a 10-coordinate geometry to four equivalent Nb(1), two equivalent B(1), two equivalent B(2), and two equivalent B(3) atoms. Both W(2)-B(1) bond lengths are 2.39 Å. Both W(2)-B(2) bond lengths are 2.39 Å. Both W(2)-B(3) bond lengths are 2.47 Å. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent W(1), four equivalent W(2), and one B(2) atom. The B(1)-B(2) bond length is 1.90 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), four equivalent W(2), and one B(1) atom. In the third B site, B(3) is bonded in a 9-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent W(1), two equivalent W(2), and one B(3) atom. The B(3)-B(3) bond length is 1.95 Å.