Non-reactive scattering of N2 from the W(110) surface studied with different exchange-correlation functionals
K R Geethalakshmi1, J I Juaristi, R Díez Muiño
1Centro de Física de Materiales (CSIC-UPV/EHU)-Materials Physics Center MPC, P. Manuel de Lardizabal 5, 20018 San Sebastián, Spain.
Physical Chemistry Chemical Physics : PCCP
|January 19, 2011
Summary
This study used classical dynamics to compare two potential energy surfaces for nitrogen molecule scattering on tungsten. The PW91 functional showed more realistic surface interactions than RPBE, especially at higher distances.
Area of Science:
- Surface Science
- Computational Chemistry
- Physical Chemistry
Background:
- Understanding gas-surface interactions is crucial for catalysis and materials science.
- Nitrogen molecule (N2) scattering on tungsten (W(110)) is a key process in surface chemistry.
- Potential energy surfaces (PESs) derived from density functional theory (DFT) are essential for modeling these interactions.
Purpose of the Study:
- To investigate the non-reactive scattering of N2 from the W(110) surface.
- To compare the accuracy of two DFT exchange-correlation functionals (PW91 and RPBE) in describing the interaction.
- To analyze the influence of PES characteristics on scattering dynamics.
Main Methods:
- Six-dimensional (6D) classical dynamics simulations were employed.
- Two distinct PESs were calculated using DFT with PW91 and RPBE functionals.
- Analysis focused on final rotational state and angular distributions of scattered N2.
Main Results:
- The PW91 PES exhibited greater corrugation than the RPBE PES across the 6D configurational space.
- PW91's characteristics, including larger corrugation and less repulsion, align better with experimental data at distances above the chemisorption well.
- The RPBE PES, with its lower corrugation, provided a better description for interactions below the chemisorption well.
Conclusions:
- The study highlights the significant impact of the exchange-correlation functional choice on the accuracy of PESs for N2/W(110) scattering.
- PW91 appears more realistic for describing N2 scattering at larger distances from the W(110) surface.
- Experimental validation is key to assessing the reliability of theoretical models in surface dynamics.
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