In-Plane and Out-of-Plane Diffraction of H2 from Metal Surfaces

FARÍAS, D.; DÍAZ, C.; RIVIÈRE, P.; BUSNENGO, H.F.; NIETO, P.; SOMERS, M.F.; KROES, G.J.; SALIN, A.; MARTÍN, F.

PHYSICAL REVIEW LETTERS

Año: 2004 vol. 93 p. 246104 - 246107

0031-9007

We have measured in-plane and out-of-plane diffraction of H2 and D2 molecular beams scattered by reactive Pd(111) and nonreactive NiAl(110) surfaces at 140 –150 meV. A comparison with six-dimensional quantum dynamics and classical trajectory calculations shows for the first time that accurate diffraction patterns can be obtained from state-of-the-art potential energy surfaces based on density functional theory. Our measurements show that, at general incidence conditions, out-of-plane diffraction is much more important than was assumed in previous experiments.