LaNi9Si2 crystallizes in the tetragonal I4_1/amd space group. La(1) is bonded in a 22-coordinate geometry to two equivalent Ni(1), sixteen equivalent Ni(2), and four equivalent Si(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 14-coordinate geometry to two equivalent La(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded to two equivalent La(1), one Ni(1), seven equivalent Ni(2), and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing NiLa2Si2Ni8 cuboctahedra. Si(1) is bonded in a 10-coordinate geometry to two equivalent La(1), two equivalent Ni(1), and eight equivalent Ni(2) atoms.
LaNi9Si2 crystallizes in the tetragonal I4_1/amd space group. La(1) is bonded in a 22-coordinate geometry to two equivalent Ni(1), sixteen equivalent Ni(2), and four equivalent Si(1) atoms. Both La(1)-Ni(1) bond lengths are 3.11 Å. There are eight shorter (3.06 Å) and eight longer (3.20 Å) La(1)-Ni(2) bond lengths. All La(1)-Si(1) bond lengths are 3.39 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 14-coordinate geometry to two equivalent La(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. All Ni(1)-Ni(2) bond lengths are 2.63 Å. All Ni(1)-Si(1) bond lengths are 2.59 Å. In the second Ni site, Ni(2) is bonded to two equivalent La(1), one Ni(1), seven equivalent Ni(2), and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing NiLa2Si2Ni8 cuboctahedra. There are a spread of Ni(2)-Ni(2) bond distances ranging from 2.42-2.58 Å. There is one shorter (2.34 Å) and one longer (2.39 Å) Ni(2)-Si(1) bond length. Si(1) is bonded in a 10-coordinate geometry to two equivalent La(1), two equivalent Ni(1), and eight equivalent Ni(2) atoms.