Structures and electronic properties of alkali metal atom-doped boron clusters MB 12 0/– (M = Li, Na, K) are determined using the CALYPSO method for the global minimum search followed by density functional theory. It is found that the global minima obtained for the neutral clusters correspond to the half-sandwich structure and those of the monoanionic clusters correspond to the boat-shaped structure. The neutral MB 12 (M = Li, Na, K) can be considered as a member of the half-sandwich doped B 12 clusters, and the geometrical pattern of anion MB 12 – (M = Li, Na, K) is a new structure that is different from other doped B 12 clusters. Natural population and chemical bonding analyses reveal that the alkali metal atom-doped boron clusters MB 12 – are characterized as charge transfer complexes, M + B 12 2– , resulting in symmetrically distributed chemical bonds and electrostatic interactions between cationic M + and boron atoms. The calculated spectra indicate that MB 12 0/– (M = Li, Na, K) has meaningful spectral features that can be compared with future experimental data. Our work enriches the varieties of geometrical structures of doped boron clusters and can provide much insight into boron nanomaterials.

The all-boron fullerenes B40−1 and B39−1 discovered in recent experiments are characterized and revealed using photoelectron spectroscopy. Except for the photoelectron spectroscopy, one may identify such boron clusters with other spectroscopic techniques, such as infrared spectra and Raman spectra. Insight into the spectral properties of boron clusters is important to understand the boron clusters and find their potential applications. In this work, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations are carried out to comparatively study the vibrational frequencies, infrared spectra, Raman spectra and electronic absorption spectra of boron clusters Bn0/−1(n = 38–40). The numerical simulations show that such boron clusters have different and meaningful spectral features. These spectral features are readily compared with future spectroscopy measurements and can be used as fingerprints to distinguish the boron clusters Bn0/−1 with different structures (cage structure or quasi-planar structure) and with different sizes (n = 38–40).

Metalloborospherenes MB0/−40 (M = Cu, Ag, and Au) are predicted. Relative energies of these metalloborospherenes suggest that Cu, Ag and Au atoms favor the exohedral configuration.

The transition metal-doped boron clusters MB24− (M = Sc, Ti, V, and Cr) have endohedral borospherene structures, MB24− (M = Mn, Fe, and Co) have similar distorted four-ring tube structures, and NiB24− has a quasi-planar structure.