Molecular Vibrational Frequencies with Multiple Quantum Protons within the Nuclear-Electronic Orbital Framework
Molecular Vibrational Frequencies with Multiple Quantum Protons within the Nuclear-Electronic Orbital Framework
复制标题
核电子轨道框架内多个量子质子的分子振动频率
DOI：
10.1021/acs.jctc.9b00665
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发表时间：
2019
影响因子：
5.5
通讯作者：
Hammes-Schiffer, Sharon
中科院分区：
文献类型：
--
作者：
Culpitt, Tanner;Yang, Yang;Schneider, Patrick E.;Pavošević, Fabijan;Hammes-Schiffer, Sharon
核电子轨道(NEO)方法在相同的量子力学水平上处理所有电子和特定的原子核，通常是质子。用多组分含时密度泛函理论(NEO-TDDFT)计算了固定经典核的质子振动激发。最近，发展了新密度泛函理论(NEO-DFT(V))方法来计算经典核和量子核组成的模式的分子振动频率。该方法使用NEO-TDDFT的输入来构造依赖于量子质子期望值和经典核坐标的扩展的NEO-Hessian。在此，设计了一些策略，用于以独立、有效和计算实用的方式将这些方法扩展到具有多个量子质子的分子。NEO-TDDFT方法被用来描述与集体核运动相对应的振动激发，例如质子振动激发的线性组合。结果表明，NEO-DFT(V)方法在分子振动中包含了最显著的非谐效应，特别是对于氢伸缩模式。这些理论策略为多组分量子化学的广泛应用铺平了道路。
The nuclear-electronic orbital (NEO) approach treats all electrons and specified nuclei, typically protons, on the same quantum mechanical level. Proton vibrational excitations can be calculated using multicomponent time-dependent density functional theory (NEO-TDDFT) for fixed classical nuclei. Recently the NEO-DFT(V) approach was developed to enable the calculation of molecular vibrational frequencies for modes composed of both classical and quantum nuclei. This approach uses input from NEO-TDDFT to construct an extended NEO Hessian that depends on the expectation values of the quantum protons as well as the classical nuclear coordinates. Herein strategies are devised for extending these approaches to molecules with multiple quantum protons in a self-contained, effective, and computationally practical manner. The NEO-TDDFT method is shown to describe vibrational excitations corresponding to collective nuclear motions, such as linear combinations of proton vibrational excitations. The NEO-DFT(V) approach is shown to incorporate the most significant anharmonic effects in the molecular vibrations, particularly for the hydrogen stretching modes. These theoretical strategies pave the way for a wide range of multicomponent quantum chemistry applications.