DOE OSTI2020
Nd20(RuSi3)3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are eight inequivalent Nd sites. In the first Nd site, Nd is bonded in a 6-coordinate geometry to two Ru and four Si atoms. There are one shorter (3.01 Å) and one longer (3.10 Å) Nd–Ru bond lengths. There are two shorter (3.16 Å) and two longer (3.49 Å) Nd–Si bond lengths. In the second Nd site, Nd is bonded to one Ru and five Si atoms to form distorted NdSi5Ru octahedra that share corners with four equivalent NdSi5Ru octahedra, corners with six NdSi5 trigonal bipyramids, and faces with six NdSi4Ru trigonal bipyramids. The corner-sharing octahedra tilt angles range from 54–59°. The Nd–Ru bond length is 3.05 Å. There are a spread of Nd–Si bond distances ranging from 3.15–3.45 Å. In the third Nd site, Nd is bonded to five Si atoms to form distorted NdSi5 trigonal bipyramids that share corners with two equivalent NdSi5Ru octahedra, corners with four equivalent NdSi4Ru trigonal bipyramids, edges with four equivalent NdSi4Ru trigonal bipyramids, faces with two equivalent NdSi5Ru octahedra, and a faceface with one NdSi5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 43°. There are a spread of Nd–Si bond distances ranging from 3.06–3.17 Å. In the fourth Nd site, Nd is bonded in a 5-coordinate geometry to one Ru and four Si atoms. The Nd–Ru bond length is 2.89 Å. There are two shorter (3.08 Å) and two longer (3.23 Å) Nd–Si bond lengths. In the fifth Nd site, Nd is bonded in a 5-coordinate geometry to one Ru and four Si atoms. The Nd–Ru bond length is 3.06 Å. There are two shorter (3.11 Å) and two longer (3.20 Å) Nd–Si bond lengths. In the sixth Nd site, Nd is bonded in a 5-coordinate geometry to one Ru and four Si atoms. The Nd–Ru bond length is 2.95 Å. There are two shorter (3.09 Å) and two longer (3.20 Å) Nd–Si bond lengths. In the seventh Nd site, Nd is bonded to one Ru and four Si atoms to form distorted NdSi4Ru trigonal bipyramids that share corners with two equivalent NdSi5Ru octahedra, corners with four NdSi5 trigonal bipyramids, edges with four NdSi4Ru trigonal bipyramids, faces with two equivalent NdSi5Ru octahedra, and a faceface with one NdSi4Ru trigonal bipyramid. The corner-sharing octahedral tilt angles are 42°. The Nd–Ru bond length is 3.03 Å. There are a spread of Nd–Si bond distances ranging from 3.07–3.26 Å. In the eighth Nd site, Nd is bonded in a 5-coordinate geometry to two Ru and three Si atoms. There are one shorter (3.02 Å) and one longer (3.04 Å) Nd–Ru bond lengths. There are a spread of Nd–Si bond distances ranging from 3.10–3.33 Å. There are three inequivalent Ru sites. In the first Ru site, Ru is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Ru–Si bond length is 2.66 Å. In the second Ru site, Ru is bonded in a 8-coordinate geometry to eight Nd atoms. In the third Ru site, Ru is bonded in a 9-coordinate geometry to eight Nd atoms. There are four inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Ru atom. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Si–Si bond length is 2.50 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Si–Si bond length is 2.50 Å. In the fourth Si site, Si is bonded in a 10-coordinate geometry to ten Nd atoms.