Reference to paper:

J. Chem. Phys. 144, 084702 (2016)

** DOI:

10.1063/1.4942198 

** Title:

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

** Authors:

Davide Migliorini, Francesco Nattino and Geert-Jan Kroes

** Contact e-mail:

d.migliorini@lic.leidenuniv.nl

** Abstract:

The fundamental understanding of molecule-surface reactions is of great importance to heterogeneous catalysis, 
motivating many theoretical and experimental studies. Even though much attention has been dedicated to the dissociative 
chemisorption of N2 on tungsten surfaces, none of the existing theoretical models has been able to quantitatively 
reproduce experimental reaction probabilities for the sticking of N2 to W(110). In this work, the dissociative 
chemisorption of N2 on W(110) has been studied with both static electronic structure and ab initio molecular dynamics 
(AIMD) calculations including the surface temperature effects through surface atom motion. Calculations have been 
performed using density functional theory, testing functionals that account for the long range van der Waals (vdW) 
interactions, which were previously only considered in dynamical calculations within the static surface approximation.
The vdW-DF2 functional improves the description of the potential energy surface for N2 on W(110), returning less deep 
molecular adsorption wells and a better ratio between the barriers for the indirect dissociation and the desorption, 
as suggested by previous theoretical work and experimental evidence. Using the vdW-DF2 functional less trapping-mediated 
dissociation is obtained compared to results obtained with standard semi-local functionals such as PBE and RPBE, 
improving agreement with experimental data at Ei = 0.9 eV. However, at Ei = 2.287 and off-normal incidence, the vdW-DF2 
AIMD underestimates the experimental reaction probabilities, showing that also with the vdW-DF2 functional the N2 on W(110) 
interaction is not yet described with quantitative accuracy.

** Description per file:

** File RevisedManuscript.pdf: 		Post-print accepted and revised manuscript.
** File SupportingInformation.pdf:	Supporting information about convergence tests.
** SubFolder FigN:			Contains figure number N of the paper in pdf and eps format.
					The folder might contain some *.dat files containing the data plotted in the figure.
** SubFolder TabM:			Contains the data used to generate table number M of the paper.
					The folder might contain some *.dat files containing the data reported in the table.

N.B. 	if a Table and a Figure refer to the same data set the actual data are stored in the Tab folder
	while in the Fig folder there is only the Figure itself.

N.B.	all the calculations using a functional of the vdW-DF family need to be performed with an additional
	input file called vdw-kernel.bindat. If the file is missing VASP will compute it before starting the 
	actual calculation but this can take a lot of time (even days)