Smits Bauke, Sah Mantu Kumar, Naskar Koushik, Adhikari Satrajit, Meyer Jörg, Somers Mark F
Leiden Institute of Chemistry, Gorlaeus Building, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
J Chem Phys. 2024 Oct 21;161(15). doi: 10.1063/5.0231559.
We present new quantum dynamical results for the reactive scattering of hydrogen molecules from a Cu(111) surface at a surface temperature of 925 K. Reaction, scattering, and diffraction probabilities are compared for results obtained using both an effective Hartree potential (EfHP) and a sudden approximation approach, implemented through the static corrugation model (SCM), to include surface temperature effects. Toward this goal, we show how the SRP48 DFT-functional and an embedded atom potential perform when used to calculate copper lattice constants and thermal expansion coefficients based on lattice dynamics calculations within the quasi-harmonic approximation. The so-calculated phonons are then used in the EfHP approach to replace the normal modes of a fictitious copper cluster used in earlier work. We find that both the EfHP and SCM approaches correctly predict the reaction probability curve broadening effect when the surface temperature is increased. Similarly, results for rovibrationally elastic scattering appear to be improved, predominantly for the SCM model. The behavior of the EfHP results appears to remain much closer to that of a Born-Oppenheimer static surface approach, which excludes any surface temperature effects. Finally, for the diffraction, we show very clear attenuation effects for the SCM approach, significantly decreasing specular diffraction probabilities at 925 K surface temperature. These results demonstrate that state-of-the-art theoretical models are able to reproduce strictly quantum mechanical scattering effects with a sudden approximation model and open up interesting opportunities for further comparisons to experimental diffraction results.
我们展示了在925K表面温度下氢分子从Cu(111)表面进行反应性散射的新量子动力学结果。比较了使用有效哈特里势（EfHP）和通过静态起伏模型（SCM）实现的突然近似方法所获得的反应、散射和衍射概率，以纳入表面温度效应。为了实现这一目标，我们展示了SRP48密度泛函理论（DFT）泛函和嵌入原子势在基于准谐近似下的晶格动力学计算中用于计算铜晶格常数和热膨胀系数时的表现。然后，将如此计算得到的声子用于EfHP方法，以取代早期工作中使用的虚拟铜簇的正常模式。我们发现，当表面温度升高时，EfHP和SCM方法都能正确预测反应概率曲线的展宽效应。同样，转动振动弹性散射的结果似乎有所改善，主要是对于SCM模型。EfHP结果的行为似乎更接近于玻恩 - 奥本海默静态表面方法，该方法排除了任何表面温度效应。最后，对于衍射，我们展示了SCM方法非常明显的衰减效应，在925K表面温度下显著降低了镜面衍射概率。这些结果表明，先进的理论模型能够用突然近似模型再现严格的量子力学散射效应，并为与实验衍射结果进行进一步比较开辟了有趣的机会。
