(675f) Convex Hulls in Computational Catalysis

Deriving thermodynamically germane quantities from molecular simulations is a central task of computational catalysis and related fields. At the low-density limit, molecular adsorbates and reaction intermediates can be thermodynamically described by their average adsorption energy as this is correctly thought to correspond to the heat and free energy of adsorption that one can (nominally) access experimentally. However, to computationally explore nonidealized catalytic systems at more realistic conditions, we must make this connection explicit so that the correct quantities are extracted from models. This talk will focus on the fundamental thermodynamics that feed into these connections as well as their practical computation using, specifically, convex hull construction. Convex hulls are extensively used in the alloy sciences but can easily be translated to computational catalysis without a great deal of modification, which will be covered. We will provide examples from our research where the utility of convex hulls are well highlighted. The talk concludes with a critique on the ubiquitous usage of the “average adsorption energy” in computational catalysis and a suggested path forward.