Structures and infrared spectroscopy of Au$_{10}$ cluster at different temperatures

TL;DR

This study investigates the finite-temperature structures and infrared spectra of Au$_{10}$ clusters using a combination of genetic algorithms, density functional theory, and nanothermodynamics, aligning computational results with experimental data.

Contribution

It introduces a comprehensive approach integrating nanothermodynamics with DFT and genetic algorithms to explore Au$_{10}$ cluster properties at finite temperatures.

Findings

The 2D elongated hexagon structure dominates from 50 to 800 K.

Calculated IR spectra at 100 K match experimental spectra.

Relativistic effects and dispersion are crucial for accurate modeling.

Abstract

Understanding the properties of Au$_{10}$ clusters entails identifying the lowest energy structure at cold and warm temperatures. While functional materials operate at finite temperatures, energy computations using density functional theory are typically performed at zero temperature, resulting in unexplored properties. Our study undertook an exploration of the potential and free energy surface of the neutral Au$_{10}$ nanocluster at finite temperatures by employing a genetic algorithm combined with density functional theory and nanothermodynamics. We computed the thermal population and infrared Boltzmann spectrum at a finite temperature, aligning the results with validated experimental data. The Zero-Order Regular Approximation (ZORA) gave consideration to relativistic effects, and dispersion was incorporated using Grimme's dispersion D3BJ with Becke-Johnson damping. Moreover, nanothermodynamics was utilized to account for temperature contributions. The computed thermal population strongly supports the dominance of the 2D elongated hexagon configuration within a temperature range of 50 to 800 K. Importantly, at a temperature of 100 K, the calculated IR Boltzmann spectrum aligns with the experimental IR spectrum. Lastly, the chemical bonding analysis on the lowest energy structure indicates a closed-shell Au-Au interaction with a weak or partially covalent character.