Probing the structural evolution and stabilities of CsB0/− (n = 2–12) clusters

To understand the effects of Cs on pure boron clusters, the growth mode, electronic properties, and bonding characteristics of CsBn0/− (n = 2–12) clusters were discussed by CALYPSO combined with DFT method. Photoelectron spectra of the ground-state structures are reliable and efficient based on the accurate structure search method, which can provide theoretical information for future related studies. Through the study of the three valid criteria, we conclude that the CsB8 and CsB8− with point group symmetry C7V have outstanding stability and electronic properties. The orbital composition analysis indicates that the molecular orbitals of these two clusters are mainly composed of B-2s and B-2p atomic orbitals (AOs), and there is a strong interaction between these two AOs. Furthermore, we also found that the high stability of CsB8 and CsB8− clusters mainly originates from the s-p bonding, σ and π bonds of B–B, especially the CsB8− cluster has (σ+π) double aromaticity.