Marsalek Ondrej, Markland Thomas E
Department of Chemistry, Stanford University , Stanford, California 94305, United States.
J Phys Chem Lett. 2017 Apr 6;8(7):1545-1551. doi: 10.1021/acs.jpclett.7b00391. Epub 2017 Mar 22.
Understanding the reactivity and spectroscopy of aqueous solutions at the atomistic level is crucial for the elucidation and design of chemical processes. However, the simulation of these systems requires addressing the formidable challenges of treating the quantum nature of both the electrons and nuclei. Exploiting our recently developed methods that provide acceleration by up to 2 orders of magnitude, we combine path integral simulations with on-the-fly evaluation of the electronic structure at the hybrid density functional theory level to capture the interplay between nuclear quantum effects and the electronic surface. Here we show that this combination provides accurate structure and dynamics, including the full infrared and Raman spectra of liquid water. This allows us to demonstrate and explain the failings of lower-level density functionals for dynamics and vibrational spectroscopy when the nuclei are treated quantum mechanically. These insights thus provide a foundation for the reliable investigation of spectroscopy and reactivity in aqueous environments.
在原子层面理解水溶液的反应活性和光谱学对于阐明和设计化学过程至关重要。然而，对这些系统进行模拟需要应对处理电子和原子核量子性质所带来的巨大挑战。利用我们最近开发的能实现高达两个数量级加速的方法，我们将路径积分模拟与混合密度泛函理论水平的电子结构即时评估相结合，以捕捉核量子效应与电子表面之间的相互作用。在此我们表明，这种结合能提供准确的结构和动力学信息，包括液态水的完整红外光谱和拉曼光谱。这使我们能够论证并解释在对原子核进行量子力学处理时，较低水平密度泛函在动力学和振动光谱学方面的不足。因此，这些见解为可靠研究水环境中的光谱学和反应活性奠定了基础。
