Hf3Ni2Si3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 9-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. In the second Hf site, Hf(2) is bonded in a 10-coordinate geometry to four equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms. Ni(1) is bonded in a 10-coordinate geometry to two equivalent Hf(1), four equivalent Hf(2), one Si(1), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1), four equivalent Hf(2), and two equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Hf(1), four equivalent Hf(2), three equivalent Ni(1), and one Si(2) atom.
Hf3Ni2Si3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 9-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), and three equivalent Si(1) atoms. All Hf(1)-Ni(1) bond lengths are 2.94 Å. Both Hf(1)-Si(2) bond lengths are 2.70 Å. There are two shorter (2.77 Å) and one longer (2.88 Å) Hf(1)-Si(1) bond length. In the second Hf site, Hf(2) is bonded in a 10-coordinate geometry to four equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms. There are a spread of Hf(2)-Ni(1) bond distances ranging from 2.81-3.01 Å. Both Hf(2)-Si(1) bond lengths are 2.70 Å. There are two shorter (2.81 Å) and two longer (2.82 Å) Hf(2)-Si(2) bond lengths. Ni(1) is bonded in a 10-coordinate geometry to two equivalent Hf(1), four equivalent Hf(2), one Si(1), and three equivalent Si(2) atoms. The Ni(1)-Si(1) bond length is 2.38 Å. There are two shorter (2.26 Å) and one longer (2.35 Å) Ni(1)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1), four equivalent Hf(2), and two equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Hf(1), four equivalent Hf(2), three equivalent Ni(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.43 Å.