DOE OSTI2020
Sr6Rh30As19 crystallizes in the trigonal P3 space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 12-coordinate geometry to six Rh and six As atoms. There are a spread of Sr–Rh bond distances ranging from 3.23–3.27 Å. There are a spread of Sr–As bond distances ranging from 3.12–3.16 Å. In the second Sr site, Sr is bonded in a 12-coordinate geometry to seven Rh and six As atoms. There are a spread of Sr–Rh bond distances ranging from 3.24–3.47 Å. There are a spread of Sr–As bond distances ranging from 3.12–3.16 Å. There are ten inequivalent Rh sites. In the first Rh site, Rh is bonded to one Rh and four As atoms to form distorted RhAs4Rh tetrahedra that share corners with six RhAs4Rh tetrahedra, edges with two equivalent RhAs4Rh2 tetrahedra, and a faceface with one RhAs4Rh2 tetrahedra. The Rh–Rh bond length is 2.89 Å. There are a spread of Rh–As bond distances ranging from 2.45–2.60 Å. In the second Rh site, Rh is bonded in a 12-coordinate geometry to two equivalent Sr, two equivalent Rh, and four As atoms. Both Rh–Rh bond lengths are 2.85 Å. There are a spread of Rh–As bond distances ranging from 2.48–2.56 Å. In the third Rh site, Rh is bonded in a 12-coordinate geometry to two equivalent Sr and four As atoms. There are a spread of Rh–As bond distances ranging from 2.48–2.57 Å. In the fourth Rh site, Rh is bonded in a 5-coordinate geometry to five As atoms. There are one shorter (2.48 Å) and four longer (2.63 Å) Rh–As bond lengths. In the fifth Rh site, Rh is bonded in a 5-coordinate geometry to five As atoms. There are one shorter (2.48 Å) and four longer (2.63 Å) Rh–As bond lengths. In the sixth Rh site, Rh is bonded in a 12-coordinate geometry to two equivalent Sr and four As atoms. There are a spread of Rh–As bond distances ranging from 2.48–2.57 Å. In the seventh Rh site, Rh is bonded in a 12-coordinate geometry to three Sr, five Rh, and four As atoms. There are one shorter (2.89 Å) and one longer (2.90 Å) Rh–Rh bond lengths. There are a spread of Rh–As bond distances ranging from 2.48–2.58 Å. In the eighth Rh site, Rh is bonded in a 12-coordinate geometry to two equivalent Sr and four As atoms. There are a spread of Rh–As bond distances ranging from 2.49–2.55 Å. In the ninth Rh site, Rh is bonded in a 12-coordinate geometry to two equivalent Sr and four As atoms. There are a spread of Rh–As bond distances ranging from 2.49–2.55 Å. In the tenth Rh site, Rh is bonded to two equivalent Rh and four As atoms to form a mixture of distorted face, edge, and corner-sharing RhAs4Rh2 tetrahedra. There are a spread of Rh–As bond distances ranging from 2.41–2.55 Å. There are seven inequivalent As sites. In the first As site, As is bonded in a 8-coordinate geometry to two equivalent Sr and six Rh atoms. In the second As site, As is bonded in a 8-coordinate geometry to two equivalent Sr and six Rh atoms. In the third As site, As is bonded in a 9-coordinate geometry to two equivalent Sr and seven Rh atoms. In the fourth As site, As is bonded in a 9-coordinate geometry to two equivalent Sr and seven Rh atoms. In the fifth As site, As is bonded in a 9-coordinate geometry to two equivalent Sr and seven Rh atoms. In the sixth As site, As is bonded in a 9-coordinate geometry to two equivalent Sr and seven Rh atoms. In the seventh As site, As is bonded in a distorted octahedral geometry to six Rh atoms.