Hertl Nils, Kandratsenka Alexander, Wodtke Alec M
Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, Göttingen, Germany.
Institut für Physikalische Chemie, Georg-August-Universität, Tammannstraße 6, Göttingen, Germany.
Phys Chem Chem Phys. 2022 Apr 13;24(15):8738-8748. doi: 10.1039/d2cp00087c.
We report a newly derived Effective Medium Theory (EMT) formalism for bcc metals and apply it for the construction of a full-dimensional PES for H atoms interacting with molybdenum (Mo) and tungsten (W). We construct PESs for the (111) and (110) facets of both metals. The EMT-PESs have the advantage that they automatically provide the background electron density on the fly which makes incorporation of ehp excitation within the framework of electronic friction straightforward. Using molecular dynamics with electronic friction (MDEF) with these new PESs, we simulated 2.76 eV H atoms scattering and adsorption. The large energy losses at a surface temperature of 300 K is very similar those seen for H atom scattering from the late fcc metals and is dominated by ehp excitation. We see significant differences in the scattering from different surface facets of the same metal. For the (110) facet, we see strong evidence of sub-surface scattering, which should be observable in experiment and we predict the best conditions for observing this novel type of scattering process. At low temperatures the MD simulations predict that H atom scattering is surface specific due to the reduced influence of the random force.
我们报告了一种新推导的体心立方金属有效介质理论（EMT）形式，并将其应用于构建氢原子与钼（Mo）和钨（W）相互作用的全维势能面（PES）。我们构建了这两种金属（111）和（110）晶面的PES。EMT - PES的优点是能即时自动提供背景电子密度，这使得在电子摩擦框架内纳入电子 - 空穴对激发变得直接。使用带有电子摩擦的分子动力学（MDEF）和这些新的PES，我们模拟了2.76 eV氢原子的散射和吸附。在300 K表面温度下的大量能量损失与从晚期面心立方金属散射的氢原子的情况非常相似，并且主要由电子 - 空穴对激发主导。我们看到同一金属不同表面晶面的散射存在显著差异。对于（110）晶面，我们看到了强烈的次表面散射证据，这在实验中应该是可观测的，并且我们预测了观测这种新型散射过程的最佳条件。在低温下，分子动力学模拟预测由于随机力影响的降低，氢原子散射具有表面特异性。
