Density functional and ab initio study of samarium dihalides, SmX₂ (X = I, Br, and Cl)

ABSTRACT

Quantum chemical calculations were performed to identify the closely lying septet electronic states of SmX₂ (X = I, Br, and Cl) and their electronic structures were analysed. According to high-level ab initio calculations, the ground state of SmX₂ (X = I, Br, and Cl) is the ⁷B₁(2) state. The molecular structures of SmX₂ (X = I, Br, and Cl) as optimised by B1B95 are very close to those obtained using coupled-cluster singles and doubles including perturbative corrections for the triple excitations (CCSD(T)). Since the electronic states of SmX₂ (X = I, Br, and Cl) are quite close, the thermal average should be considered to compare the calculated results with the experimental ones. Descriptions of the molecular properties of SmX₂ (X = I, Br, and Cl) are correlated to the ability to accurately describe the ionic bonding character of SmX₂ (X = I, Br, and Cl).

GRAPHICAL ABSTRACT

KEYWORDS:

• Density functional theory
• ab initio calculation
• lanthanide
• samarium dihalide

Acknowledgments

This research was supported by Basic Science Research Programme through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2016R1D1A1B03933120). This work was supported by the Catholic University of Korea, Research Fund, 2018. This work was also supported by the National Institute of Supercomputing and Network/Korea Institute of Science and Technology Information with supercomputing resources including technical support (KSC-2018-C2-0003).

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Joonghan Kim http://orcid.org/0000-0002-7783-0200

Additional information

Funding

This research was supported by National Research Foundation of Korea [grant number NRF-2016R1D1A1B03933120]; National Institute of Supercomputing and Network/Korea Institute of Science and Technology Information [grant number KSC-2018-C2-0003].