Self-interaction errors in first-row transition metal molecular adsorption energies*

The binding of adsorbate molecules at metal sites is relevant for a number of applications such as catalysis and storage (H₂). In particular, metal organic frameworks (MOFs) with open mental sites are drawing attention for these applications. A recent study on a Cu(I)-substituted MOF^₁ showed that density functional theory (DFT) with LDA, PBE, and SCAN functionals tend to overestimate the adsorption energies of small molecules at Cu(I) centers. Another study² showed that the adsorption energies of H₂ molecules on monocationic 3d metals is overestimated by LDA, GGA, and mGGA functionals, while hybrid and double hybrid functionals tend to perform better. In this work we use the Fermi-Löwdin orbital (FLO) self interaction correction (SIC) method to compute adsorption energies of a series of small molecules on 3d transition metal cations. Results indicate that the FLO-SIC corrects LDA and PBE adsorption energies towards accurate reference values. We will also report results for molecular adsorption energies in cluster models of MOF binding sites.
¹Organometallics, 38, 3453-3459 (2019)
²J. Chem. Theory Comput., 16, 4963-4982 (2020)