Rapid Access to Ground- and Excited-State Properties of Gold Nanoclusters Coated with Organic Ligands: Evaluation of the DFTB Method Performance

Gold nanoclusters stand as promising building blocks for solar energy harvesting applications, luminescent materials, and catalytic devices. At the frontier between molecular and metallic structures, their large number of electrons prevent the use of the ab initio quantum mechanics method to rationalize and predict their structure-property relationships, especially when fully coated with organic ligands. Using an approximate DFT-based scheme, namely, the density functional tight-binding (DFTB), we demonstrate that it is possible to rapidly access the ground- (geometry and electronic structure) and excited-state (UV-visible absorption) properties of these nano-objects without sacrificing the qualitative accuracy of its parent DFT, paving the way toward a quantum material design of gold-organic nanodevices.