Size effects and electronic properties of zinc-doped boron clusters Zn B n (n = 1-15)

Abstract

Context: To gain a deeper understanding of zinc-doped boron clusters, theoretical calculations were performed to investigate the size effects and electronic properties of zinc-doped boron clusters. The study of the electronic properties, spectral characteristics, and geometric structures of Zn ${\text{B}}_n$ (n = 1-15) is of great significance in the fields of semiconductor materials science, material detection, and improving catalytic efficiency. The results indicate that Zn ${\text{B}}_n$ (n = 1-15) clusters predominantly exhibit planar or quasi-planar structures, with the Zn atom positioned in the outer regions of the ${\text{B}}_n$ framework. The second stable structure of Zn ${\text{B}}_3$ is a three-dimensional configuration, indicating that the structures of zinc-doped boron clusters begin to convert from the planar or quasi-planar structures to the 3D configurations. The second low-energy structure of Zn ${\text{B}}_{15}$ is a novel configuration. Relative stability analyses show that the Zn ${\text{B}}_{12}$ has better chemical stability than other clusters with a HOMO-LUMO gap of 2.79 eV. Electric charge analysis shows that part electrons on zinc atoms are transferred to boron atoms, and electrons prefer to cluster near the ${\text{B}}_n$ framework. According to the electron localization function, it gets harder to localize electrons as the equivalent face value drops, and it's challenging to see covalent bond formation between zinc and boron atoms. The spectrograms of Zn ${\text{B}}_n$ (n = 1-15) exhibit distinct properties and notable spectral features, which can be used as a theoretical basis for the identification and confirmation of boron clusters doped with single-atom transition metals.

Methods: The calculations were performed using the ABCluster global search technique combined with density functional theory (DFT) methods. The selected low-energy structures were subjected to geometric optimization and frequency calculations at the PBE0/6-311 $+$ G(d) level to ensure structural stability and eliminate any imaginary frequencies. To acquire more precise relative energies, we performed single-point energies calculations for the low-lying isomers of Zn ${\text{B}}_n$ (n = 1-15) at the CCSD(T)/6-311 $+$ G(d)//PBE0/6-311 $+$ G(d) level of theory. All calculations were performed using Gaussian 09 software. To facilitate analysis, we utilized software tools such as Multiwfn, and VMD.

Keywords: Density functional theory; Geometric and electronic properties; Spectral characteristics; Zinc-boron cluster.