NdNiB4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. In the second Nd site, Nd(2) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. Ni(1) is bonded to two equivalent Nd(1), two equivalent Nd(2), two equivalent Ni(1), two equivalent B(1), and four equivalent B(2) atoms to form a mixture of distorted corner, edge, and face-sharing NiNd4Ni2B6 cuboctahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), one Ni(1), two equivalent B(1), and two equivalent B(2) atoms. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), two equivalent Ni(1), one B(2), and two equivalent B(1) atoms.
NdNiB4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. All Nd(1)-Ni(1) bond lengths are 3.09 Å. All Nd(1)-B(1) bond lengths are 2.89 Å. There are four shorter (2.84 Å) and four longer (2.91 Å) Nd(1)-B(2) bond lengths. In the second Nd site, Nd(2) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. All Nd(2)-Ni(1) bond lengths are 3.00 Å. All Nd(2)-B(1) bond lengths are 2.89 Å. All Nd(2)-B(2) bond lengths are 2.85 Å. Ni(1) is bonded to two equivalent Nd(1), two equivalent Nd(2), two equivalent Ni(1), two equivalent B(1), and four equivalent B(2) atoms to form a mixture of distorted corner, edge, and face-sharing NiNd4Ni2B6 cuboctahedra. Both Ni(1)-Ni(1) bond lengths are 2.47 Å. Both Ni(1)-B(1) bond lengths are 2.11 Å. All Ni(1)-B(2) bond lengths are 2.23 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), one Ni(1), two equivalent B(1), and two equivalent B(2) atoms. There is one shorter (1.73 Å) and one longer (1.77 Å) B(1)-B(1) bond length. Both B(1)-B(2) bond lengths are 1.76 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), two equivalent Ni(1), one B(2), and two equivalent B(1) atoms. The B(2)-B(2) bond length is 1.73 Å.