Be12Nb crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded in a 12-coordinate geometry to two equivalent Be(1), four equivalent Be(2), four equivalent Be(3), and two equivalent Nb(1) atoms. In the second Be site, Be(2) is bonded in a 10-coordinate geometry to one Be(2), four equivalent Be(1), four equivalent Be(3), and one Nb(1) atom. In the third Be site, Be(3) is bonded to two equivalent Be(3), four equivalent Be(1), four equivalent Be(2), and two equivalent Nb(1) atoms to form a mixture of distorted edge, corner, and face-sharing BeBe10Nb2 cuboctahedra. Nb(1) is bonded in a 20-coordinate geometry to four equivalent Be(2), eight equivalent Be(1), and eight equivalent Be(3) atoms.
Be12Nb crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Be sites. In the first Be site, Be(1) is bonded in a 12-coordinate geometry to two equivalent Be(1), four equivalent Be(2), four equivalent Be(3), and two equivalent Nb(1) atoms. Both Be(1)-Be(1) bond lengths are 2.26 Å. There are two shorter (2.32 Å) and two longer (2.34 Å) Be(1)-Be(2) bond lengths. All Be(1)-Be(3) bond lengths are 2.13 Å. Both Be(1)-Nb(1) bond lengths are 2.64 Å. In the second Be site, Be(2) is bonded in a 10-coordinate geometry to one Be(2), four equivalent Be(1), four equivalent Be(3), and one Nb(1) atom. The Be(2)-Be(2) bond length is 2.17 Å. All Be(2)-Be(3) bond lengths are 2.24 Å. The Be(2)-Nb(1) bond length is 2.58 Å. In the third Be site, Be(3) is bonded to two equivalent Be(3), four equivalent Be(1), four equivalent Be(2), and two equivalent Nb(1) atoms to form a mixture of distorted edge, corner, and face-sharing BeBe10Nb2 cuboctahedra. Both Be(3)-Be(3) bond lengths are 2.10 Å. Both Be(3)-Nb(1) bond lengths are 2.80 Å. Nb(1) is bonded in a 20-coordinate geometry to four equivalent Be(2), eight equivalent Be(1), and eight equivalent Be(3) atoms.