(695g) Fast and Accurate Assessment of Electronic Structure Changes of Nanocatalysts upon Alloying and Adsorption

The accurate description of shifts in the d-bands center of metallic systems during alloying and adsorption is a crucial factor in predicting their catalytic activity trends. However, for complex compositions such as nanoparticles or Van der Waals heterostructures, computing electronic properties through ab-initio methods such as density functional theory (DFT) is computationally very expensive or, with increasing system size, unfeasible.
Tight-binding (TB) approaches such as the self-charge-consistent density functional tight binding (SCC-DFTB) method offer an appealing alternative, reducing these demanding tasks to seconds or minutes even for large systems, with a negligible loss in accuracy. With an average performance of three orders of magnitude faster than DFT, SCC-DFTB allows for work on system sizes up to the nanoscale while still retaining ab-initio information.

Our research has resulted in the development database of so-called Slater-Koster files that contain the TB overlap matrices describing the electronic information of every possible d-element pairing. These sets of parameters, when incorporated into the DFTB+ software, accurately describe the density of states and band structures of any (bi-)metallic alloy in a matter of minutes. During our contribution at the conference, we will explain how our established TB routine enables the immediate identification of shifts in the d-bands center during subsurface alloying and the adsorption of O, H, C, and N species.

We are confident that our method represents an important breakthrough for the computational catalysis community, as it guarantees transferability to complex systems that would otherwise be inaccessible to any other ab-initio method.