Materials Data on FeP4 by Materials Project

Abstract

FeP4 is Sylvanite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six P+0.75- atoms to form FeP6 octahedra that share corners with two equivalent FeP6 octahedra, corners with nine PFeP3 tetrahedra, and an edgeedge with one FeP6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Fe–P bond distances ranging from 2.18–2.32 Å. In the second Fe3+ site, Fe3+ is bonded to six P+0.75- atoms to form FeP6 octahedra that share corners with six PFeP3 tetrahedra and edges with two equivalent FeP6 octahedra. All Fe–P bond lengths are 2.25 Å. There are six inequivalent P+0.75- sites. In the first P+0.75- site, P+0.75- is bonded to one Fe3+ and three P+0.75- atoms to form distorted PFeP3 tetrahedra that share corners with five FeP6 octahedra and corners with two PFe2P2 tetrahedra. The corner-sharing octahedra tilt angles range from 62–79°. There are a spread of P–P bond distances ranging from 2.18–2.29 Å. In the second P+0.75- site, P+0.75- is bonded in a 4-coordinate geometry to two equivalent Fe3+ and two P+0.75- atoms. The P–P bond length is 2.24 Å. In the third P+0.75- site, P+0.75- is bonded in a 4-coordinate geometry to two Fe3+ and two P+0.75- atoms. There are one shorter (2.22 Å) and one longer (2.23 Å) P–P bond lengths. In the fourth P+0.75- site, P+0.75- is bonded to two Fe3+ and two P+0.75- atoms to form distorted PFe2P2 tetrahedra that share corners with three FeP6 octahedra and corners with five PFeP3 tetrahedra. The corner-sharing octahedra tilt angles range from 64–70°. In the fifth P+0.75- site, P+0.75- is bonded to one Fe3+ and three P+0.75- atoms to form distorted PFeP3 tetrahedra that share corners with four equivalent FeP6 octahedra and corners with five PFeP3 tetrahedra. The corner-sharing octahedra tilt angles range from 45–80°. The P–P bond length is 2.26 Å. In the sixth P+0.75- site, P+0.75- is bonded in a distorted single-bond geometry to one Fe3+ and three P+0.75- atoms. The P–P bond length is 2.30 Å.