Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
J Am Chem Soc. 2022 Mar 9;144(9):4039-4046. doi: 10.1021/jacs.1c12932. Epub 2022 Feb 24.
Nuclear quantum effects play a crucial role in many chemical and biological systems involving hydrogen atoms yet are difficult to include in practical molecular simulations. In this paper, we combine our recently developed methods of constrained nuclear-electronic orbital density functional theory (cNEO-DFT) and constrained minimized energy surface molecular dynamics (CMES-MD) to create a new method for accurately and efficiently describing nuclear quantum effects in molecular simulations. By use of this new method, dubbed cNEO-MD, the vibrational spectra of a set of small molecules are calculated and compared with those from conventional molecular dynamics (AIMD) as well as from experiments. With the same formal scaling, cNEO-MD greatly outperforms AIMD in describing the vibrational modes with significant hydrogen motion characters, demonstrating the promise of cNEO-MD for simulating chemical and biological systems with significant nuclear quantum effects.
核量子效应在涉及氢原子的许多化学和生物系统中起着至关重要的作用，但很难将其纳入实际的分子模拟中。在本文中，我们结合了我们最近开发的约束核电子轨道密度泛函理论（cNEO-DFT）和约束最小化能量表面分子动力学（CMES-MD）方法，创建了一种新的方法，用于在分子模拟中准确有效地描述核量子效应。通过使用这种新方法，我们计算了一组小分子的振动光谱，并将其与传统的分子动力学（AIMD）和实验结果进行了比较。在相同的形式标度下，cNEO-MD 在描述具有显著氢运动特征的振动模式方面优于 AIMD，这表明 cNEO-MD 有望用于模拟具有显著核量子效应的化学和生物系统。
