Materials Data on Pr2Ni7 by Materials Project
Pr2Ni7 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Pr sites. In the first Pr site, Pr is bonded in a 12-coordinate geometry to twelve Ni atoms. There are a spread of Pr–Ni bond distances ranging from 2.91–3.25 Å. In the second Pr site, Pr is bonded in a 6-coordinate geometry to eighteen Ni atoms. There are a spread of Pr–Ni bond distances ranging from 2.93–3.32 Å. There are five inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Pr and six Ni atoms. There are three shorter (2.46 Å) and three longer (2.50 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded to six equivalent Pr and six equivalent Ni atoms to form NiPr6Ni6 cuboctahedra that share corners with twelve equivalent NiPr5Ni7 cuboctahedra, edges with six equivalent NiPr6Ni6 cuboctahedra, and faces with eighteen equivalent NiPr5Ni7 cuboctahedra. All Ni–Ni bond lengths are 2.61 Å. In the third Ni site, Ni is bonded to four equivalent Pr and eight Ni atoms to form NiPr4Ni8 cuboctahedra that share corners with sixteen NiPr5Ni7 cuboctahedra, edges with ten NiPr5Ni7 cuboctahedra, and faces with ten NiPr4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.48–2.54 Å. In the fourth Ni site, Ni is bonded to five Pr and seven Ni atoms to form distorted NiPr5Ni7 cuboctahedra that share corners with seventeen NiPr6Ni6 cuboctahedra, edges with eight NiPr4Ni8 cuboctahedra, and faces with fourteen NiPr6Ni6 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.48–2.54 Å. In the fifth Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Pr and six Ni atoms.