DOE OSTI2020
Zr2Fe12P7 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are two inequivalent Zr sites. In the first Zr site, Zr is bonded in a 12-coordinate geometry to twelve Fe and six equivalent P atoms. There are a spread of Zr–Fe bond distances ranging from 2.91–3.15 Å. All Zr–P bond lengths are 2.81 Å. In the second Zr site, Zr is bonded in a 12-coordinate geometry to nine Fe and six equivalent P atoms. There are six shorter (2.89 Å) and three longer (3.06 Å) Zr–Fe bond lengths. All Zr–P bond lengths are 2.77 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to three Zr and four P atoms to form a mixture of distorted corner, edge, and face-sharing FeZr3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.18–2.29 Å. In the second Fe site, Fe is bonded to one Zr and four P atoms to form a mixture of distorted corner, edge, and face-sharing FeZrP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.12–2.25 Å. In the third Fe site, Fe is bonded to three Zr and four P atoms to form a mixture of distorted corner, edge, and face-sharing FeZr3P4 tetrahedra. There are one shorter (2.20 Å) and three longer (2.26 Å) Fe–P bond lengths. In the fourth Fe site, Fe is bonded in a 5-coordinate geometry to five P atoms. There are a spread of Fe–P bond distances ranging from 2.26–2.52 Å. There are three inequivalent P sites. In the first P site, P is bonded in a 9-coordinate geometry to two equivalent Zr and seven Fe atoms. In the second P site, P is bonded in a 9-coordinate geometry to two equivalent Zr and seven Fe atoms. In the third P site, P is bonded in a 3-coordinate geometry to nine Fe atoms.