Materials Data on Y2HfS5 by Materials Project

Y2HfS5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Y–S bond distances ranging from 2.82–2.99 Å. Hf4+ is bonded to seven S2- atoms to form distorted edge-sharing HfS7 pentagonal bipyramids. There are a spread of Hf–S bond distances ranging from 2.51–2.69 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to four equivalent Y3+ and one Hf4+ atom to form distorted SY4Hf trigonal bipyramids that share corners with four equivalent SY4Hf square pyramids, corners with four equivalent SY2Hf2 tetrahedra, corners with five SY4Hf trigonal bipyramids, an edgeedge with one SY4Hf square pyramid, edges with four equivalent SY2Hf2 tetrahedra, edges with four equivalent SY4Hf trigonal bipyramids, and a faceface with one SY4Hf square pyramid. In the second S2- site, S2- is bonded to four equivalent Y3+ and one Hf4+ atom to form distorted SY4Hf square pyramids that share corners with eight equivalent SY2Hf2 tetrahedra, corners with nine SY4Hf trigonal bipyramids, edges with two equivalent SY4Hf square pyramids, edges with two equivalent SY2Hf2 tetrahedra, edges with three SY4Hf trigonal bipyramids, and a faceface with one SY4Hf trigonal bipyramid. In the third S2- site, S2- is bonded to four equivalent Y3+ and one Hf4+ atom to form distorted SY4Hf trigonal bipyramids that share corners with five equivalent SY4Hf square pyramids, corners with four equivalent SY2Hf2 tetrahedra, corners with five SY4Hf trigonal bipyramids, edges with two equivalent SY4Hf square pyramids, edges with four equivalent SY2Hf2 tetrahedra, and edges with four equivalent SY4Hf trigonal bipyramids. In the fourth S2- site, S2- is bonded to two equivalent Y3+ and two equivalent Hf4+ atoms to form distorted SY2Hf2 tetrahedra that share corners with four equivalent SY4Hf square pyramids, corners with six equivalent SY2Hf2 tetrahedra, corners with four SY4Hf trigonal bipyramids, an edgeedge with one SY4Hf square pyramid, an edgeedge with one SY2Hf2 tetrahedra, and edges with four SY4Hf trigonal bipyramids.