# Molecule-surface interaction from van der Waals-corrected semilocal density functionals: the example of thiophene on transition-metal surfaces

## TL;DR

This paper evaluates various semi-local density functionals, especially with vdW corrections, for accurately modeling thiophene adsorption on transition-metal surfaces, emphasizing the importance of balanced short- and long-range interactions.

## Contribution

It demonstrates the effectiveness of vdW-corrected semi-local density functionals in predicting adsorption energies and geometries for thiophene on metal surfaces.

## Key findings

- vdW corrections improve adsorption energy predictions
- SCAN functional estimates intermediate-range vdW effects well
- balanced short- and long-range correlation is crucial for accuracy

## Abstract

Semi-local density functional approximations are widely used. None of them can capture the long-range van der Waals (vdW) attraction between separated subsystems, but they differ remarkably in the extent to which they capture intermediate-range vdW effects responsible for equilibrium bonds between neighboring small closed-shell subsystems. The local density approximation (LDA) often overestimates this effect, while the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) underestimates it. The strongly-constrained and appropriately normed (SCAN) meta-GGA often estimates it well. All of these semi-local functionals require an additive non-local correction such as the revised Vydrov-Van Voorhis 2010 (rVV10) to capture the long-range part. This work reports adsorption energies and the corresponding geometry of the aromatic thiophene (C$_4$H$_4$S) bound to transition metal surfaces. The adsorption process requires a genuine interplay of covalent and weak binding and requires a simultaneously accurate description of surface and adsorption energies with the correct prediction of the adsorption site. All these quantities must come from well balanced short and long-range correlation effects for a universally applicable method for weak interactions with chemical accuracy.