DOE OSTI2020
Ce2Fe12P7 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a 12-coordinate geometry to twelve Fe and six equivalent P atoms. There are a spread of Ce–Fe bond distances ranging from 2.97–3.21 Å. All Ce–P bond lengths are 2.91 Å. In the second Ce site, Ce is bonded in a 12-coordinate geometry to nine Fe and six equivalent P atoms. There are six shorter (2.95 Å) and three longer (3.12 Å) Ce–Fe bond lengths. All Ce–P bond lengths are 2.87 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to three Ce and four P atoms to form a mixture of distorted face, edge, and corner-sharing FeCe3P4 tetrahedra. There are two shorter (2.26 Å) and two longer (2.30 Å) Fe–P bond lengths. In the second Fe site, Fe is bonded to one Ce and four P atoms to form a mixture of distorted face, edge, and corner-sharing FeCeP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.13–2.28 Å. In the third Fe site, Fe is bonded to three Ce and four P atoms to form a mixture of distorted face, edge, and corner-sharing FeCe3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.26–2.33 Å. 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 2.26–2.53 Å. There are three inequivalent P sites. In the first P site, P is bonded in a 9-coordinate geometry to two equivalent Ce and seven Fe atoms. In the second P site, P is bonded in a 9-coordinate geometry to two equivalent Ce and seven Fe atoms. In the third P site, P is bonded in a 3-coordinate geometry to nine Fe atoms.