Surrogate adsorption energy exchange-correlation functional difference model using electron density-derived features

Abstract

In this work, we develop a surrogate adsorption energy difference model to predict the difference in adsorption energy in the LDA xc and the PBE xc in small hydrocarbons on the Pt(111) surface. By fitting adsorbate atoms’ DDEC6 bond orders to the metallic surface and the overall charge transfer, we build an interpretable model based on atom-atom electron overlap that estimates adsorption energy difference to approximately 0.06 eV mean absolute error. We then apply the model to Ni, Ir, and Pd surfaces by accounting for the lattice constant to estimate the adsorption energy difference within 0.06 eV. Importantly, corrections can easily be understood and related to LDA and PBE’s different treatments of the systems’ atoms’ electron density overlaps and overall charge transfer from the adsorbate to the surface.