Role of the dispersion force in modeling the interfacial properties of molecule-metal interfaces: adsorption of thiophene on copper surfaces

摘要

We present density functional theory calculations of the geometry, adsorptionenergy and electronic structure of thiophene adsorbed on Cu(111), Cu(110) andCu(100) surfaces. Our calculations employ dispersion corrections andself-consistent van der Waals density functionals (vdW-DFs). In terms of speedand accuracy, we find that the dispersion-energy-corrected RevisedPerdue-Burke-Enzerhof (RPBE) functional is the "best balanced" method forpredicting structural and energetic properties, while vdW-DF is also highlyaccurate if a proper exchange functional is used. Discrepancies between theoryand experiment in molecular geometry can be solved by considering x-raygenerated core-holes. However, the discrepancy concerning the adsorption sitefor thiophene/Cu(100) remains unresolved and requires both further experimentsand deeper theoretical analysis. For all the interfaces, the PBE functionalreveals a covalent bonding picture which the inclusion of dispersivecontributions does not change to a vdW one. Our results provide a comprehensiveunderstanding of the role of dispersive forces in modelling molecule-metalinterfaces.