La3Ni4Si4 crystallizes in the orthorhombic Immm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), four equivalent Ni(2), two equivalent Si(2), and four equivalent Si(1) atoms. In the second La site, La(2) is bonded to four equivalent Ni(2) and eight equivalent Si(2) atoms to form a mixture of face and edge-sharing LaSi8Ni4 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to two equivalent La(2), four equivalent La(1), one Si(1), and two 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 four equivalent La(1), one Ni(2), and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent La(1), four equivalent La(2), two equivalent Ni(2), and one Si(2) atom.
La3Ni4Si4 crystallizes in the orthorhombic Immm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), four equivalent Ni(2), two equivalent Si(2), and four equivalent Si(1) atoms. There are two shorter (3.11 Å) and two longer (3.18 Å) La(1)-Ni(1) bond lengths. All La(1)-Ni(2) bond lengths are 3.16 Å. Both La(1)-Si(2) bond lengths are 3.12 Å. All La(1)-Si(1) bond lengths are 3.17 Å. In the second La site, La(2) is bonded to four equivalent Ni(2) and eight equivalent Si(2) atoms to form a mixture of face and edge-sharing LaSi8Ni4 cuboctahedra. All La(2)-Ni(2) bond lengths are 3.14 Å. All La(2)-Si(2) bond lengths are 3.18 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Si(1) atoms. There are two shorter (2.37 Å) and two longer (2.38 Å) Ni(1)-Si(1) bond lengths. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to two equivalent La(2), four equivalent La(1), one Si(1), and two equivalent Si(2) atoms. The Ni(2)-Si(1) bond length is 2.39 Å. Both Ni(2)-Si(2) bond lengths are 2.35 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent La(1), one Ni(2), and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent La(1), four equivalent La(2), two equivalent Ni(2), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.44 Å.