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

Autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF CLUSTER SCIENCE; v. 31, n. 6, p. 8-pg., 2019-11-12.

Resumo

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)

• Processo FAPESP: 17/11631-2 - CINE: desenvolvimento computacional de materiais utilizando simulações atomísticas, meso-escala, multi-física e inteligência artificial para aplicações energéticas
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia