DOE OSTI2020
Ce3Ti6Fe23 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a 1-coordinate geometry to one Ti and seventeen Fe atoms. The Ce–Ti bond length is 3.16 Å. There are a spread of Ce–Fe bond distances ranging from 2.96–3.38 Å. In the second Ce site, Ce is bonded in a 12-coordinate geometry to four Ti and sixteen Fe atoms. There are two shorter (2.99 Å) and two longer (3.01 Å) Ce–Ti bond lengths. There are a spread of Ce–Fe bond distances ranging from 3.03–3.33 Å. There are three inequivalent Ti sites. In the first Ti site, Ti is bonded in a 12-coordinate geometry to one Ce, one Ti, and ten Fe atoms. The Ti–Ti bond length is 2.66 Å. There are a spread of Ti–Fe bond distances ranging from 2.61–2.84 Å. In the second Ti site, Ti is bonded in a 10-coordinate geometry to one Ce, one Ti, and eight Fe atoms. The Ti–Ti bond length is 2.67 Å. There are a spread of Ti–Fe bond distances ranging from 2.60–2.78 Å. In the third Ti site, Ti is bonded in a 12-coordinate geometry to one Ce, one Ti, and ten Fe atoms. There are a spread of Ti–Fe bond distances ranging from 2.56–2.86 Å. There are eight inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Ce, two Ti, and eight Fe atoms to form distorted FeCe2Ti2Fe8 cuboctahedra that share corners with fifteen FeCe2Ti2Fe8 cuboctahedra, edges with two FeCe3TiFe8 cuboctahedra, and faces with thirteen FeCe2Ti2Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.46–2.67 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to two Ce, three Ti, and seven Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.42–2.49 Å. In the third Fe site, Fe is bonded in a 2-coordinate geometry to two equivalent Ti and eight Fe atoms. All Fe–Fe bond lengths are 2.49 Å. In the fourth Fe site, Fe is bonded to two Ce, four Ti, and six Fe atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with eighteen FeCe2Ti2Fe8 cuboctahedra, edges with four FeCe3TiFe8 cuboctahedra, and faces with seven FeCe2Ti2Fe8 cuboctahedra. There are two shorter (2.49 Å) and two longer (2.69 Å) Fe–Fe bond lengths. In the fifth Fe site, Fe is bonded in a 12-coordinate geometry to two Ce, three Ti, and seven Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.53–2.73 Å. In the sixth Fe site, Fe is bonded to three equivalent Ce, one Ti, and eight Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeCe3TiFe8 cuboctahedra. There are one shorter (2.43 Å) and one longer (2.48 Å) Fe–Fe bond lengths. In the seventh Fe site, Fe is bonded to three Ce, one Ti, and eight Fe atoms to form a mixture of distorted face, edge, and corner-sharing FeCe3TiFe8 cuboctahedra. In the eighth Fe site, Fe is bonded to two equivalent Ce, four Ti, and six Fe atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with twelve FeCe2Ti2Fe8 cuboctahedra, edges with four FeCe3TiFe8 cuboctahedra, and faces with eight FeCe2Ti2Fe8 cuboctahedra.