Neutral and Anionic Gold Decamers: Planar Structure with Unusual Spatial Charge-Spin Separation

Area of Science:

• Computational Chemistry
• Materials Science
• Atomic and Molecular Physics

Background:

• Determining the lowest-energy structure of gold clusters is crucial for understanding their properties.
• Previous studies primarily utilized density functional theory (DFT), with varying conclusions on dimensionality.

Purpose of the Study:

• To resolve the debate on 2D versus 3D structures for neutral Au10.
• To identify the lowest-energy structure among 2D Au10(-) isomers.
• To investigate the influence of relativistic effects and computational methods on structural determination.

Main Methods:

• Extensive density functional theory (DFT) calculations.
• High-level ab initio calculations, including Möller-Plesset second order perturbation theory (MP2) and coupled cluster theory with single and double excitations [CCSD(T)].
• Basis-set superposition error (BSSE) corrections were applied.

Main Results:

• DFT calculations favored 2D structures, while MP2 and CCSD(T) initially favored 3D structures.
• BSSE corrections shifted ab initio results towards favoring 2D structures.
• Relativistic effects stabilize acute apex gold atoms, promoting 2D configurations.
• Planar triangular Au10 and Au10(-) exhibit significant charge-spin separation.
• Au10(-) shows a substantially larger vertical detachment energy compared to other even-numbered gold cluster anions.

Conclusions:

• The lowest-energy structure for Au10 and its anion is predominantly 2D.
• Relativistic effects play a key role in stabilizing 2D gold clusters.
• Charge-spin separation in planar structures leads to unique electronic properties in Au10(-)