Density functional theory-based study on the structural, electronic and spectral properties of gas-phase PbMg _{<i>n</i> ⁻} ( <i>n</i> = 2–12) clusters

Gas-phase PbMg _<i>n^-</i> (<i>n</i> = 2-12) cluster structures were globally searched on their potential energy surfaces by means of the CALYPSO prediction software. Structural optimization and calculations of properties such as relative energy and electronic structure were then carried out by density functional theory for each size of low energy isomer. The structural, relative stability, natural charge population, natural electronic configuration and distribution of the strongest peaks of the infrared and Raman spectra of the low energy isomers of PbMg _<i>n^-</i> (<i>n</i> = 2-12) clusters were systematically investigated in the present work. It was shown that the PbMg_7^- cluster ground state isomer exhibits the highest stability, for which special electronic excitation and chemical bonding analyses were performed. It is reasonable to believe that this work enriches the structural, spectroscopic and other data of magnesium-based clusters and provides some theoretical basis for possible future experimental syntheses.