SmNiB4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(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 Sm site, Sm(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 in a 6-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent B(2), and four 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 two equivalent Sm(1), two equivalent Sm(2), two equivalent Ni(1), one 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 Sm(1), two equivalent Sm(2), one Ni(1), two equivalent B(1), and two equivalent B(2) atoms.
SmNiB4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. All Sm(1)-Ni(1) bond lengths are 2.99 Å. All Sm(1)-B(1) bond lengths are 2.82 Å. All Sm(1)-B(2) bond lengths are 2.87 Å. In the second Sm site, Sm(2) is bonded in a 20-coordinate geometry to four equivalent Ni(1), eight equivalent B(1), and eight equivalent B(2) atoms. All Sm(2)-Ni(1) bond lengths are 3.06 Å. There are four shorter (2.80 Å) and four longer (2.90 Å) Sm(2)-B(1) bond lengths. All Sm(2)-B(2) bond lengths are 2.87 Å. Ni(1) is bonded in a 6-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent B(2), and four equivalent B(1) atoms. Both Ni(1)-B(2) bond lengths are 2.09 Å. All Ni(1)-B(1) bond lengths are 2.20 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent Ni(1), one B(1), and two equivalent B(2) atoms. The B(1)-B(1) bond length is 1.72 Å. Both B(1)-B(2) bond lengths are 1.75 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), one Ni(1), two equivalent B(1), and two equivalent B(2) atoms. There is one shorter (1.71 Å) and one longer (1.77 Å) B(2)-B(2) bond length.