A Hybrid Density Functional Theory Investigation of the (CeO2)(6) Clusters in the Cationic, Neutral, and Anionic States

Author(s)

Ozorio, Mailde S. ; Da Silva, Augusto C. H. ; Da Silva, Juarez L. F.

• Document type: Journal article
• Source: JOURNAL OF CLUSTER SCIENCE; v. 31, n. 6, p. 8-pg., 2019-11-12.

Abstract

We report a quantum-chemistry investigation of the cationic, neutral, and anionic oCeO2 6 clusters to obtain an atom-level understanding of the effects induced by the release or addition of a single electron on the physical and chemical properties of small oxide clusters. Our ab initio calculations are based on density functional theory (DFT) within the hybrid Heyd-Scuseria-Ernzerhof (HSE06) and semilocal Perdew-Burke-Ernzerhof (PBE) functional. Compared with PBE, the HSE06 functional changes the relative stability of the neutral oCeO2 6 isomers, in particular, for structures with small total energy differences, e.g., about 100 meV/fu, which can be explained by the enhancement of the exchange interactions. The addition of an electron to the oCeO2 6 clusters change the oxidation state of a single Ce atom from ? IV to ? III, which drives a local distortion and the formation of a small polaron near to the CeIII cation. In contrast, the release of an electron induces the formation of a localized hole on one of the O atoms combined with local structural distortions. For the anionic and cationic clusters in the putative global minimum configurations, we found a strain energy induced by the distortion of 1.00 and 1.31 eV, respectively. (AU)

• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program