DOI: 10.17188/1728326
title: Materials Data on UNi3P2 by Materials Project

description: UNi3P2 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are two inequivalent U3+ sites. In the first U3+ site, U3+ is bonded to six P3- atoms to form distorted UP6 pentagonal pyramids that share corners with four equivalent UP6 pentagonal pyramids, corners with two equivalent NiP5 square pyramids, corners with twelve NiP4 tetrahedra, edges with two equivalent UP6 pentagonal pyramids, edges with eight NiP4 tetrahedra, and faces with two equivalent UP6 pentagonal pyramids. There are a spread of U–P bond distances ranging from 2.88–2.96 Å. In the second U3+ site, U3+ is bonded to six P3- atoms to form distorted UP6 pentagonal pyramids that share corners with four UP6 pentagonal pyramids, corners with two equivalent NiP5 square pyramids, corners with twelve NiP4 tetrahedra, edges with two UP6 pentagonal pyramids, an edgeedge with one NiP5 square pyramid, edges with seven NiP4 tetrahedra, and faces with two equivalent UP6 pentagonal pyramids. There are a spread of U–P bond distances ranging from 2.80–2.92 Å. There are six inequivalent Ni1+ sites. In the first Ni1+ site, Ni1+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with eight equivalent UP6 pentagonal pyramids, corners with six NiP4 tetrahedra, edges with two equivalent UP6 pentagonal pyramids, edges with two equivalent NiP5 square pyramids, and edges with four equivalent NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.22–2.29 Å. In the second Ni1+ site, Ni1+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with six UP6 pentagonal pyramids, a cornercorner with one NiP5 square pyramid, corners with six NiP4 tetrahedra, edges with four UP6 pentagonal pyramids, and edges with four NiP4 tetrahedra. There are three shorter (2.28 Å) and one longer (2.37 Å) Ni–P bond lengths. In the third Ni1+ site, Ni1+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with four equivalent UP6 pentagonal pyramids, corners with eleven NiP4 tetrahedra, edges with three UP6 pentagonal pyramids, edges with two equivalent NiP5 square pyramids, and edges with three NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.30–2.36 Å. In the fourth Ni1+ site, Ni1+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with four equivalent UP6 pentagonal pyramids, corners with four equivalent NiP5 square pyramids, corners with seven NiP4 tetrahedra, edges with three equivalent UP6 pentagonal pyramids, an edgeedge with one NiP5 square pyramid, and edges with four NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.27–2.35 Å. In the fifth Ni1+ site, Ni1+ is bonded to five P3- atoms to form distorted NiP5 square pyramids that share corners with six UP6 pentagonal pyramids, corners with ten NiP4 tetrahedra, edges with two equivalent UP6 pentagonal pyramids, edges with two equivalent NiP5 square pyramids, and edges with eight NiP4 tetrahedra. There are one shorter (2.33 Å) and four longer (2.54 Å) Ni–P bond lengths. In the sixth Ni1+ site, Ni1+ is bonded in a trigonal planar geometry to three P3- atoms. There are one shorter (2.20 Å) and two longer (2.24 Å) Ni–P bond lengths. There are four inequivalent P3- sites. In the first P3- site, P3- is bonded in a 9-coordinate geometry to two equivalent U3+ and seven Ni1+ atoms. In the second P3- site, P3- is bonded in a 9-coordinate geometry to four U3+ and five Ni1+ atoms. In the third P3- site, P3- is bonded in a 9-coordinate geometry to four equivalent U3+ and five Ni1+ atoms. In the fourth P3- site, P3- is bonded in a 9-coordinate geometry to two equivalent U3+ and seven Ni1+ atoms.