Influence of the van der Waals interaction in the dissociation dynamics of N2 on W(110) from first principles

Abstract

Calculation of the structure, potential energy surface, vibrational dynamics, and electric dipole properties for the Xe:HI van der Waals complex J. Chem. Phys. 134, 174302 (2011) ] exchange-correlation functionals were unable to fully describe the dependence of the initial sticking coefficient on the molecular beam incidence conditions as found in experiments. N 2 dissociation on W(110) was shown to be very sensitive not only to short molecule-surface distances but also to large distances where the vdW interaction, not included in semilocal-DFT, should dominate. In this work, we perform a systematic study on the dissociative adsorption using a selection of existing non-local functionals that include the vdW interaction (vdW-functionals). Clearly, the inclusion of the non-local correlation term contributes in all cases to correct the unrealistic energy barriers that were identified in the RPBE at large molecule-surface distances. Among the tested vdW-functionals, the original vdW-DF by Dion et al. [Phys. Rev. Lett. 92, 246401 (2004)] and the ulterior vdW-DF2 give also an adequate description of the N 2 adsorption energy and energy barrier at the transition state, i.e., of the properties that are commonly used to verify the quality of any exchange-correlation functional. However, the results of our AIMD calculations, which are performed at different incidence conditions and hence extensively probe the multi-configurational potential energy surface of the system, do not seem as satisfactory as the preliminary static analysis suggested. When comparing the obtained dissociation probabilities with existing experimental data, none of the used vdW-functionals seems to provide altogether an adequate description of the N 2 /W(110) interaction at short and large distances. C 2015 AIP Publishing LLC.[http://dx

Application of van der Waals functionals to the calculation of dissociative adsorption of N2 on W(110) for static and dynamic systems

“…For the vdW-DF functional, the molecular adsorption energies calculated are very similar to the PBE results. Moreover previous static surface AIMD simulations performed by Martin-Gondre et al 17 showed an underestimation of the experimental reaction probability using this functional. Therefore in this work we focus on the more promising vdW-DF2 functional.…”

“…There is experimental 18,41 and theoretical 10,11,15,17 evidence for the existence of molecular adsorption states of N 2 on W(110). The associated configurations are believed to be relevant to the indirect dissociation mechanism in which the molecule remains trapped near the surface before dissociating.…”

“…17 and testing both the vdW-DF and the vdW-DF2 functionals. We have also performed AIMD calculations for N 2 impinging on the W(110) surface using the vdW-DF2 functional, simultaneously accounting for both the effect of the long range vdW interactions and the effect of surface atom motion on the dissociation probability.…”

“…17 The authors performed a static study of some vdW functionals and computed reaction probability for a few energies with AIMD in the frozen surface approximation (AIMD-FS). Some of the functionals studied improve the static properties of the PES, giving less deep molecular adsorption wells and returning barriers for the desorption and for the dissociation from the molecular adsorption states closer to each other than found with semilocal functionals, in better agreement with experimental evidence.…”

N2 dissociation on W(110): An ab initio molecular dynamics study on the effect of phonons

“…In a very recent study [29], the dissociation of N 2 on W(110) has been investigated using density functionals in which the correlation has been corrected to account for dispersion interactions [30,31]. The authors have shown that some of these density functionals better describe properties such as adsorption energy and barriers for dissociation and desorption from the adsorption configuration that they have determined.…”