First-principles characterisation of spectroscopic and bonding properties of cationic bismuth carbide clusters

Abstract

Vibrational and electronic absorption spectra calculated at the (time-dependent) density functional theory level for the bismuth carbide clusters Bi n C + 2n (3 ≤ n ≤ 9) indicate significant differences in types of bonding that depend on cluster geometry.Analysis of the electronic charge densities of these clusters highlighted bonding trends consistent with the spectroscopic information. The combined data suggest that larger clusters (n > 5) are likely to be kinetically unstable in agreement with the cluster mass distribution obtained in gas-aggregation source experiments. The spectral fingerprints of the different clusters obtained from our calculations also suggest that identification of specific Bi n C + 2n isomers of should be possible based on infra-red and optical absorption spectroscopy.