DOE OSTI2020
Sm2Fe12P7 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 12-coordinate geometry to twelve Fe and six P atoms. There are a spread of Sm–Fe bond distances ranging from 3.00–3.17 Å. There are two shorter (2.90 Å) and four longer (2.91 Å) Sm–P bond lengths. In the second Sm site, Sm is bonded in a 12-coordinate geometry to nine Fe and six P atoms. There are a spread of Sm–Fe bond distances ranging from 2.98–3.10 Å. All Sm–P bond lengths are 2.86 Å. There are twelve inequivalent Fe sites. In the first Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are one shorter (2.28 Å) and three longer (2.29 Å) Fe–P bond lengths. In the second Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.27–2.29 Å. In the third Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are one shorter (2.28 Å) and three longer (2.29 Å) Fe–P bond lengths. In the fourth Fe site, Fe is bonded to one Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSmP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.14–2.28 Å. In the fifth Fe site, Fe is bonded to one Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSmP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.15–2.29 Å. In the sixth Fe site, Fe is bonded to one Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSmP4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.15–2.29 Å. In the seventh Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.26–2.34 Å. In the eighth Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.27–2.35 Å. In the ninth Fe site, Fe is bonded to three Sm and four P atoms to form a mixture of distorted edge, face, and corner-sharing FeSm3P4 tetrahedra. There are a spread of Fe–P bond distances ranging from 2.27–2.34 Å. In the tenth 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 2.25–2.53 Å. In the eleventh 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. In the twelfth 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 2.25–2.53 Å. There are seven inequivalent P sites. In the first P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the second P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the third P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the fourth P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the fifth P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the sixth P site, P is bonded in a 9-coordinate geometry to two equivalent Sm and seven Fe atoms. In the seventh P site, P is bonded in a 3-coordinate geometry to nine Fe atoms.