MgNi3B2 crystallizes in the hexagonal P6_422 space group. Mg(1) is bonded in a 18-coordinate geometry to two equivalent Mg(1), four equivalent Ni(2), eight equivalent Ni(1), and four equivalent B(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 6-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms. B(1) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Ni(2), four equivalent Ni(1), and one B(1) atom.
MgNi3B2 crystallizes in the hexagonal P6_422 space group. Mg(1) is bonded in a 18-coordinate geometry to two equivalent Mg(1), four equivalent Ni(2), eight equivalent Ni(1), and four equivalent B(1) atoms. Both Mg(1)-Mg(1) bond lengths are 2.90 Å. All Mg(1)-Ni(2) bond lengths are 2.82 Å. There are four shorter (2.66 Å) and four longer (3.02 Å) Mg(1)-Ni(1) bond lengths. All Mg(1)-B(1) bond lengths are 2.60 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 6-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms. There are two shorter (1.99 Å) and two longer (2.04 Å) Ni(1)-B(1) bond lengths. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms. All Ni(2)-B(1) bond lengths are 2.21 Å. B(1) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Ni(2), four equivalent Ni(1), and one B(1) atom. The B(1)-B(1) bond length is 1.90 Å.