Materials Data on LaSiNi4 by Materials Project
LaNi4Si is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. La is bonded in a 6-coordinate geometry to fourteen Ni and four equivalent Si atoms. There are a spread of La–Ni bond distances ranging from 2.86–3.16 Å. All La–Si bond lengths are 3.29 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent La, five Ni, and two equivalent Si atoms. There are four shorter (2.50 Å) and one longer (2.61 Å) Ni–Ni bond lengths. Both Ni–Si bond lengths are 2.37 Å. In the second Ni site, Ni is bonded to four equivalent La, six Ni, and two equivalent Si atoms to form NiLa4Si2Ni6 cuboctahedra that share corners with four equivalent SiLa4Ni8 cuboctahedra, corners with twelve equivalent NiLa4Si2Ni6 cuboctahedra, edges with four equivalent SiLa4Ni8 cuboctahedra, edges with six equivalent NiLa4Si2Ni6 cuboctahedra, faces with four equivalent SiLa4Ni8 cuboctahedra, and faces with six equivalent NiLa4Si2Ni6 cuboctahedra. Both Ni–Ni bond lengths are 2.62 Å. Both Ni–Si bond lengths are 2.46 Å. Si is bonded to four equivalent La and eight Ni atoms to form distorted SiLa4Ni8 cuboctahedra that share corners with eight equivalent NiLa4Si2Ni6 cuboctahedra, corners with eight equivalent SiLa4Ni8 cuboctahedra, edges with two equivalent SiLa4Ni8 cuboctahedra, edges with eight equivalent NiLa4Si2Ni6 cuboctahedra, faces with two equivalent SiLa4Ni8 cuboctahedra, and faces with eight equivalent NiLa4Si2Ni6 cuboctahedra.