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

Abstract

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 PdMg _2 and PdMg _3 . Stability studies indicate that PdMg _4 , PdMg _7 , PdMg _10 , and PdMg _15 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 PdMg _6 and PdMg _7 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.

Keywords

• CALYPSO
• DFT
• PdMg n clusters
• Pd-doped