Structural evolution, stability, electronic and bonding properties of sodium-doped magnesium cluster cations

Abstract

Bimetallic sodium-doped magnesium cluster cations, NaMg_n⁺(n= 2–12), have been investigated through a synergetic combination of the CALYPSO code and DFT calculations. The results reveal that the lowest-energy structures of NaMg_n⁺ exhibit linear, planar, triangular pyramid, pentagonal pyramid, and triangular prism topologies. The structures can be described as a substituted geometry of pure Mg clusters at the small size. Starting from n = 9, the dominant structures transform into a triangular prism-based configuration. Like anionic and neutral NaMg_n clusters, the Na atom prefers the peripheral regions of the Mg_n framework. Stability studies indicate NaMg₄⁺ and NaMg₁₀⁺ to be the~most stable clusters, which may benefit from their closed-shell electron structures. Analysis of the bonding nature shows stronger Mg-Mg interaction than the Na-Mg interaction in the NaMg₄⁺ and NaMg₁₀⁺ clusters. The reason is that covalent bonds are formed in the Mg-Mg regions, while there is no aggregation of electron density in the Na-Mg regions.

GRAPHICAL ABSTRACT

KEYWORDS:

• DFT
• CALYPSO
• NaMg_n⁺ clusters
• structures
• electronic properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the Natural Science Basic Research Plan in Shaanxi Province of China (grant number 2023-JC-YB-464).