Ground state structures and properties of Be atom doped boron clusters BeB\begin{document}$ _{ n}^{\bf 0/-} $\end{document}(\begin{document}$ n \bf = 10$\end{document}–15)

Abstract

A theoretical study of geometrical structures and electronic properties of Be atom doped boron clusters BeB<inline-formula><tex-math id="Z-20201005110528-1">\begin{document}$ _n^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110528-1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110528-1.png"/></alternatives></inline-formula>(<i>n</i> = 10–15) is performed using the CALYPSO approach for the global minimum search followed by density functional theory calculations. It is found that the global minima obtained for the BeB<inline-formula><tex-math id="Z-20201005110850-1">\begin{document}$ _{10}^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-1.png"/></alternatives></inline-formula>, BeB<inline-formula><tex-math id="Z-20201005110850-2">\begin{document}$ _{11}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-2.png"/></alternatives></inline-formula>, BeB<inline-formula><tex-math id="Z-20201005110850-3">\begin{document}$ _{12}^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-3.png"/></alternatives></inline-formula>, and BeB<inline-formula><tex-math id="Z-20201005110850-4">\begin{document}$ _{14}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-4.png"/></alternatives></inline-formula> clusters correspond to the quasi-planar or planar structures. However, the global minima obtained for the BeB₁₁, BeB₁₃, BeB<inline-formula><tex-math id="Z-20201005110850-5">\begin{document}$ _{13}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-5.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-5.png"/></alternatives></inline-formula>, BeB₁₄ clusters correspond to the half-sandwich, cone, cage, squashed tubular structures, respectively. Interestingly, both the neutral and anionic BeB<inline-formula><tex-math id="Z-20201005110850-6">\begin{document}$ _{15}^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-6.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110850-6.png"/></alternatives></inline-formula> clusters have the axially chiral isomers which are chiral with degenerate enantiomers. Natural population analyses reveal that partial charge on Be atom transfer to boron atoms. The average binding energy values of BeB<inline-formula><tex-math id="Z-20201005110651-1">\begin{document}$ _n^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110651-1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110651-1.png"/></alternatives></inline-formula><i> </i>(<i>n</i> = 10–15) indicate that anionic clusters are overall more stable than the corresponding neutral ones, and both neutral and anionic clusters show the same trend that the stability increases gradually with the increase of B atoms number n. Chemical bonding analyses of closed-shell BeB₁₀, BeB<inline-formula><tex-math id="Z-20201005110931-1">\begin{document}$ _{11}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-1.png"/></alternatives></inline-formula>, BeB₁₂ clusters reveal that the σ bonds stabilize whole molecular skeleton, and delocalized π bonds render the structure more stable. Furthermore, the three quasi-planar closed-shell clusters possess 3 delocalized π bonds, which quite surprisingly follow the 4<i>m</i> + 2 Hückel rule for aromaticity. Average polarizability of single atom for each quasi-planar or planar structure is larger than other structures, it indicates that quasi-planar or planar structure has stronger electron delocalization. Specifically, BeB<inline-formula><tex-math id="Z-20201005110931-2">\begin{document}$ _{13}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-2.png"/></alternatives></inline-formula> and BeB<inline-formula><tex-math id="Z-20201005110931-3">\begin{document}$ _{14}^{-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110931-3.png"/></alternatives></inline-formula> with large first static hyperpolarizability can lead to the remarkable NLO response. The calculated spectra indicate that BeB<inline-formula><tex-math id="Z-20201005110528-2">\begin{document}$ _n^{0/-} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110528-2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="19-20200756_Z-20201005110528-2.png"/></alternatives></inline-formula>(<i>n</i> = 10–15) have the meaningful characteristic peaks which can be compared with future experimental values. Our work enriches the database of geometrical structures of doped boron clusters and can provide much insight into the new doped boron clusters.