NdNiSi2 crystallizes in the orthorhombic Cmcm space group. Nd(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), four equivalent Si(1), and six equivalent Si(2) atoms. Ni(1) is bonded in a 9-coordinate geometry to four equivalent Nd(1), one Si(2), and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to four equivalent Nd(1) and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to six equivalent Nd(1), one Ni(1), and two equivalent Si(2) atoms.
NdNiSi2 crystallizes in the orthorhombic Cmcm space group. Nd(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), four equivalent Si(1), and six equivalent Si(2) atoms. All Nd(1)-Ni(1) bond lengths are 3.14 Å. There are two shorter (3.10 Å) and two longer (3.14 Å) Nd(1)-Si(1) bond lengths. There are four shorter (3.09 Å) and two longer (3.18 Å) Nd(1)-Si(2) bond lengths. Ni(1) is bonded in a 9-coordinate geometry to four equivalent Nd(1), one Si(2), and four equivalent Si(1) atoms. The Ni(1)-Si(2) bond length is 2.30 Å. There are two shorter (2.32 Å) and two longer (2.36 Å) Ni(1)-Si(1) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to four equivalent Nd(1) and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to six equivalent Nd(1), one Ni(1), and two equivalent Si(2) atoms. Both Si(2)-Si(2) bond lengths are 2.43 Å.