Revisiting the global minimum of Au10 clusters

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Understanding the global minimum structure of gold clusters is crucial for their catalytic and electronic properties.
• Previous studies have proposed different structures for Au10 clusters, leading to ambiguity.

Purpose of the Study:

• To definitively determine the global minimum structure of Au10 clusters.
• To investigate the influence of spin-orbit coupling on Au10 cluster structures.
• To propose a method for identifying strong spin-orbit coupling in gold clusters.

Main Methods:

• High-level quantum chemical calculations, including coupled-cluster singles and doubles with perturbative triples [CCSD(T)].
• Utilized quadruple-ζ basis sets and incorporated spin-orbit (SO) effects.
• Employed two-component spin-orbit density functional theory (DFT) calculations.

Main Results:

• The planar 10.b structure is identified as the true global minimum for Au10, contradicting previous reports of the 3D 10.a structure.
• Spin-orbit effects were found to be minimal for most Au10 isomers, with notable exceptions.
• A diagnostic tool based on 6p orbital occupation was proposed for identifying strong SO coupling.
• Calculated IR spectra showed good agreement with experimental data, suggesting minor discrepancies may arise from Kr interactions.

Conclusions:

• The global minimum structure of Au10 clusters is planar (10.b).
• The transition to non-planar global minimum structures in gold clusters occurs beyond Au10.
• The proposed diagnostic tool offers a new method for analyzing spin-orbit coupling effects in gold clusters.