5-step algorithm to accelerate the prediction of [Au25(SR)19]z clusters (z = 1−, 0, 1+)

Abstract

Prediction of the structure of thiolated gold clusters is time demanding, and new strategies are needed to expedite this process. In this study, using one five-step algorithm and dispersion corrected density functional theory (DFT-D) calculations, new models are proposed for neutral and charged Au₂₅(SR)₁₉ clusters that contain one extra ligand with respect to the ubiquitous Au₂₅(SR)₁₈ cluster. The algorithm counts for constituting tetrahedra/octahedra units of related isomers, and it provides their energy order. In general, one structure comprising one Au₁₁ inner core is found as energy minima of neutral and charged Au₂₅(SR)₁₉ clusters. Therefore, our new neutral structure is 0.20 eV (–CH₃ and TPSS) more stable than the previously reported one. With respect to neutral and anionic structures containing inner cores with C_2v symmetry, ultraviolet-visible/circular dichroism profiles are similar.