Performance of dispersion corrected DFT for the weak interaction between aromatic molecules and extended carbon-based systems
D. Mollenhauer, C. Brieger, E. Voloshina, B. Paulus – 2015
The performance of different DFT approaches in combination with dispersion correction is studied for the interaction between aromatic molecules and extended carbon-based materials on the example of the pyridine–graphene system. The basic interaction is modeled using graphene fragments of increasing size as well as periodic boundary conditions. Different DFT-D2/D3 methods are tested for small and medium fragment systems in comparison to wave-function-based CCSD(T) and SCS-MP2 approaches. Furthermore, the adsorption energy between pyridine and extended graphene sheets or periodic modeled graphene calculated by DFT-D2/D3 or nonlocal correlation functionals (vdW-DF) is compared to experimental values. The study of DFT-D performance along different scales reveals the dispersion correction as too strong along increasing graphene fragment sizes. Finally, this leads to different methodology advice for small and extended pyridine–graphene systems.