Nd2Ni5B4 crystallizes in the monoclinic C2/m space group. Nd(1) is bonded in a 16-coordinate geometry to three equivalent Ni(2), eight equivalent Ni(1), two equivalent B(2), and three equivalent B(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to four equivalent Nd(1), two equivalent B(1), and two equivalent B(2) atoms. In the second Ni site, Ni(2) is bonded in a distorted linear geometry to six equivalent Nd(1) and two equivalent B(2) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to three equivalent Nd(1), four equivalent Ni(1), one B(1), and one B(2) atom. In the second B site, B(2) is bonded in a 8-coordinate geometry to two equivalent Nd(1), one Ni(2), four equivalent Ni(1), and one B(1) atom.
Nd2Ni5B4 crystallizes in the monoclinic C2/m space group. Nd(1) is bonded in a 16-coordinate geometry to three equivalent Ni(2), eight equivalent Ni(1), two equivalent B(2), and three equivalent B(1) atoms. There are two shorter (3.12 Å) and one longer (3.36 Å) Nd(1)-Ni(2) bond length. There are a spread of Nd(1)-Ni(1) bond distances ranging from 2.92-3.24 Å. Both Nd(1)-B(2) bond lengths are 2.86 Å. There is one shorter (2.89 Å) and two longer (2.93 Å) Nd(1)-B(1) bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to four equivalent Nd(1), two equivalent B(1), and two equivalent B(2) atoms. There is one shorter (2.08 Å) and one longer (2.10 Å) Ni(1)-B(1) bond length. There is one shorter (2.02 Å) and one longer (2.19 Å) Ni(1)-B(2) bond length. In the second Ni site, Ni(2) is bonded in a distorted linear geometry to six equivalent Nd(1) and two equivalent B(2) atoms. Both Ni(2)-B(2) bond lengths are 2.03 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to three equivalent Nd(1), four equivalent Ni(1), one B(1), and one B(2) atom. The B(1)-B(1) bond length is 1.74 Å. The B(1)-B(2) bond length is 1.68 Å. In the second B site, B(2) is bonded in a 8-coordinate geometry to two equivalent Nd(1), one Ni(2), four equivalent Ni(1), and one B(1) atom.