Relativistic DFT calculations for neutral and singly charged Au2

The study explores the use of relativistic Density Functional Theory (DFT) using the Gaussian09 package to analyze the geometry optimization of gold diatoms in various ionic states. The optimization is performed at multiple theoretical levels, including B3LYP, cam-B3LYP, PBEPBE, HSE1PBE, and HSE2PBE, utilizing SDD and LaNL2MB basis sets. An investigation has been conducted on all structures to analyze their ionization potential, electron affinity, electrostatic potential contours, infrared spectra, molecular orbitals, energy gap, and electronic excitation. The ionization potential and electron affinity of all structures exhibit strong agreement with the experimental results. The molecular orbitals of bonding and anti-bonding nature undergo significant changes based on the ionic state. The electron charge density in a gold diatom determines the electrostatic potential contours, vibration frequency, and electronic excitation.