Bonding properties of molecular cerium oxides tuned by the 4f-block from ab initio perspective

Probing chemical bonding in molecules containing lanthanide elements is of theoretical interest, yet it is computationally challenging because of the large valence space, relativistic effects, and considerable electron correlation. We report a high-level ab initio study that quantifies the many-body nature of Ce-O bonding with the coordination environment of the Ce center and particularly the roles of the 4f orbitals. The growing significance of the overlap between Ce 4f and O 2p orbitals with the increasing coordination of Ce atoms enhances Ce-O bond covalency and in return directs the molecular geometry. Upon partial reduction from neutral to anionic ceria, the excessive electrons populate the Ce-centered localized 4f orbital. The interplay between the admixture and localization of the 4f-block dually modulates bonding patterns of cerium oxide molecules, underlying the importance of many-body interactions between ligands and various lanthanide elements. Published under an exclusive license by AIP Publishing.

Automated summary

Probing chemical bonding in molecules containing lanthanide elements is computationally challenging due to the large valence space, relativistic effects, and electron correlation. This study quantifies the many-body nature of Ce-O bonding and the roles of 4f orbitals in the coordination environment of Ce. The overlap between Ce 4f and O 2p orbitals enhances Ce-O bond covalency and directs the molecular geometry, modulating bonding patterns of cerium oxide molecules.