A single palladium atom immerses in magnesium clusters: PdMg n (n=2-20) clusters DFT study

The structure, stability, charge transfer, and chemical bonding properties of palladium-doped magnesium clusters, PdMg n (n = 2-20), are comprehensively researched by CALYPSO software within first-principles DFT computations. It is shown that the cluster structure evolved from a tetrahedral-based structure to a cage-like structure, and interestingly, the single Pd atom always immerses in the Mg- n clusters except for PdMg2 and PdMg3. Stability studies indicate that PdMg4, PdMg7, PdMg10, and PdMg15 clusters have relative robust stability and can be identified as 'magic' clusters. Most importantly, chemical bonding studies reveal that Pd-Mg is always non-covalent bond (closed-shell) interaction in all PdMg n (n = 2-20) clusters, and PdMg6 and PdMg7 are the critical sizes at which Mg-Mg covalent interactions occur. The geometric structure database of transition metal-doped Mg clusters will be enriched by this study, and it also provides, at least theoretically, new members of cage-like structures for magnesium-based hydrogen storage nanomaterials.

Automated summary

The study comprehensively investigates the structure, stability, charge transfer, and chemical bonding properties of palladium-doped magnesium clusters using the CALYPSO software and first-principles DFT computations. The research enriches the geometric structure database of transition metal-doped Mg clusters and provides theoretical insights into new cage-like structures for magnesium-based hydrogen storage nanomaterials. The results show that Pd-Mg interactions are non-covalent bonds, with PdMg6 and PdMg7 being critical sizes for Mg-Mg covalent interactions.