DOI: 10.17188/1701649
title: Materials Data on Hf27(Si3P5)2 by Materials Project

description: Hf27Si6P10 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are nine inequivalent Hf sites. In the first Hf site, Hf is bonded in a distorted rectangular see-saw-like geometry to one Si and three P atoms. The Hf–Si bond length is 2.87 Å. There are a spread of Hf–P bond distances ranging from 2.69–2.77 Å. In the second Hf site, Hf is bonded in a 4-coordinate geometry to three Si and one P atom. There are two shorter (2.67 Å) and one longer (2.86 Å) Hf–Si bond lengths. The Hf–P bond length is 2.65 Å. In the third Hf site, Hf is bonded to two equivalent Si and three P atoms to form distorted HfSi2P3 trigonal bipyramids that share corners with two equivalent HfP6 pentagonal pyramids, corners with two equivalent HfSi2P3 trigonal bipyramids, an edgeedge with one HfP6 pentagonal pyramid, edges with two equivalent HfSi2P3 trigonal bipyramids, and a faceface with one HfSi2P3 trigonal bipyramid. Both Hf–Si bond lengths are 2.73 Å. There are one shorter (2.61 Å) and two longer (2.69 Å) Hf–P bond lengths. In the fourth Hf site, Hf is bonded in a 4-coordinate geometry to three equivalent Si and two equivalent P atoms. There are two shorter (2.75 Å) and one longer (3.10 Å) Hf–Si bond lengths. Both Hf–P bond lengths are 2.72 Å. In the fifth Hf site, Hf is bonded in a 4-coordinate geometry to three Si and two equivalent P atoms. There are two shorter (2.74 Å) and one longer (3.23 Å) Hf–Si bond lengths. Both Hf–P bond lengths are 2.70 Å. In the sixth Hf site, Hf is bonded in a 6-coordinate geometry to two equivalent Si and four equivalent P atoms. Both Hf–Si bond lengths are 2.79 Å. All Hf–P bond lengths are 2.75 Å. In the seventh Hf site, Hf is bonded to six P atoms to form a mixture of distorted face, edge, and corner-sharing HfP6 pentagonal pyramids. There are two shorter (2.68 Å) and four longer (2.75 Å) Hf–P bond lengths. In the eighth Hf site, Hf is bonded to six P atoms to form distorted HfP6 pentagonal pyramids that share corners with four equivalent HfP6 pentagonal pyramids, corners with four equivalent HfSi2P3 trigonal bipyramids, edges with four HfP6 pentagonal pyramids, edges with two equivalent HfSi2P3 trigonal bipyramids, and faces with three equivalent HfP6 pentagonal pyramids. There are two shorter (2.69 Å) and four longer (2.76 Å) Hf–P bond lengths. In the ninth Hf site, Hf is bonded in a distorted square co-planar geometry to two equivalent Si and two equivalent P atoms. Both Hf–Si bond lengths are 2.95 Å. Both Hf–P bond lengths are 2.68 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to nine Hf atoms. In the second Si site, Si is bonded in a 9-coordinate geometry to nine Hf atoms. There are four inequivalent P sites. In the first P site, P is bonded in a 8-coordinate geometry to eight Hf atoms. In the second P site, P is bonded in a 8-coordinate geometry to eight Hf atoms. In the third P site, P is bonded in a 8-coordinate geometry to eight Hf atoms. In the fourth P site, P is bonded to seven Hf atoms to form a mixture of distorted edge and corner-sharing PHf7 pentagonal bipyramids.