DOE OSTI2020
Yb10Ni28As19 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are four inequivalent Yb2+ sites. In the first Yb2+ site, Yb2+ is bonded to six As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with four equivalent YbAs6 pentagonal pyramids, corners with two equivalent NiAs5 square pyramids, corners with twelve NiAs4 tetrahedra, edges with two equivalent YbAs6 pentagonal pyramids, edges with eight NiAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. There are a spread of Yb–As bond distances ranging from 3.02–3.04 Å. In the second Yb2+ site, Yb2+ is bonded to six As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with four equivalent YbAs6 pentagonal pyramids, corners with two equivalent NiAs5 square pyramids, corners with twelve NiAs4 tetrahedra, edges with two equivalent YbAs6 pentagonal pyramids, an edgeedge with one NiAs5 square pyramid, edges with seven NiAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. There are a spread of Yb–As bond distances ranging from 2.97–3.05 Å. In the third Yb2+ site, Yb2+ is bonded to six equivalent As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with six equivalent NiAs5 square pyramids, corners with twelve NiAs4 tetrahedra, edges with three equivalent NiAs5 square pyramids, edges with nine NiAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. All Yb–As bond lengths are 2.96 Å. In the fourth Yb2+ site, Yb2+ is bonded to six As3- atoms to form distorted YbAs6 pentagonal pyramids that share corners with eight YbAs6 pentagonal pyramids, corners with eight NiAs4 tetrahedra, edges with four YbAs6 pentagonal pyramids, edges with four NiAs4 tetrahedra, and faces with two equivalent YbAs6 pentagonal pyramids. There are four shorter (3.02 Å) and two longer (3.04 Å) Yb–As bond lengths. There are ten inequivalent Ni+1.32+ sites. In the first Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with six YbAs6 pentagonal pyramids, a cornercorner with one NiAs5 square pyramid, corners with six NiAs4 tetrahedra, edges with four YbAs6 pentagonal pyramids, and edges with four NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.39–2.44 Å. In the second Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with two equivalent YbAs6 pentagonal pyramids, corners with two equivalent NiAs5 square pyramids, corners with twelve NiAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, edges with two equivalent NiAs5 square pyramids, and edges with three NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.33–2.45 Å. In the third Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with six YbAs6 pentagonal pyramids, corners with two equivalent NiAs5 square pyramids, corners with six NiAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, an edgeedge with one NiAs5 square pyramid, and edges with four NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.38–2.43 Å. In the fourth Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with six YbAs6 pentagonal pyramids, corners with two equivalent NiAs5 square pyramids, corners with five NiAs4 tetrahedra, edges with four YbAs6 pentagonal pyramids, and edges with four NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.37–2.41 Å. In the fifth Ni+1.32+ site, Ni+1.32+ is bonded in a trigonal planar geometry to three As3- atoms. There are a spread of Ni–As bond distances ranging from 2.27–2.31 Å. In the sixth Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with four YbAs6 pentagonal pyramids, corners with three equivalent NiAs5 square pyramids, corners with eight NiAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, an edgeedge with one NiAs5 square pyramid, and edges with four NiAs4 tetrahedra. There are one shorter (2.38 Å) and three longer (2.40 Å) Ni–As bond lengths. In the seventh Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with four YbAs6 pentagonal pyramids, corners with eleven NiAs4 tetrahedra, edges with three YbAs6 pentagonal pyramids, edges with two equivalent NiAs5 square pyramids, and edges with three NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.33–2.43 Å. In the eighth Ni+1.32+ site, Ni+1.32+ is bonded to four As3- atoms to form NiAs4 tetrahedra that share corners with eight YbAs6 pentagonal pyramids, corners with six NiAs4 tetrahedra, edges with two YbAs6 pentagonal pyramids, edges with two equivalent NiAs5 square pyramids, and edges with four NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.32–2.35 Å. In the ninth Ni+1.32+ site, Ni+1.32+ is bonded in a trigonal planar geometry to three equivalent As3- atoms. All Ni–As bond lengths are 2.34 Å. In the tenth Ni+1.32+ site, Ni+1.32+ is bonded to five As3- atoms to form distorted NiAs5 square pyramids that share corners with six YbAs6 pentagonal pyramids, corners with ten NiAs4 tetrahedra, edges with two YbAs6 pentagonal pyramids, edges with two equivalent NiAs5 square pyramids, and edges with eight NiAs4 tetrahedra. There are a spread of Ni–As bond distances ranging from 2.39–2.70 Å. There are seven inequivalent As3- sites. In the first As3- site, As3- is bonded in a 3-coordinate geometry to six equivalent Yb2+ and three equivalent Ni+1.32+ atoms. In the second As3- site, As3- is bonded in a 9-coordinate geometry to two equivalent Yb2+ and seven Ni+1.32+ atoms. In the third As3- site, As3- is bonded in a 9-coordinate geometry to four equivalent Yb2+ and five Ni+1.32+ atoms. In the fourth As3- site, As3- is bonded in a 9-coordinate geometry to two equivalent Yb2+ and seven Ni+1.32+ atoms. In the fifth As3- site, As3- is bonded in a 9-coordinate geometry to two equivalent Yb2+ and seven Ni+1.32+ atoms. In the sixth As3- site, As3- is bonded in a 9-coordinate geometry to four Yb2+ and five Ni+1.32+ atoms. In the seventh As3- site, As3- is bonded in a 9-coordinate geometry to four Yb2+ and five Ni+1.32+ atoms.