Molecular dynamics with nuclear quantum effects: bridging classical and quantum regimes

在这个由化学系化学理论、模型和计算方法计划资助的项目中，南卡罗来纳大学哥伦比亚分校的Sophya Garashchuk教授正在开发新的理论方法来分析分子运动的动力学。这种方法将量子力学处理的分子中电子的微观行为与遵循艾萨克·牛顿的经典力学处理的原子核的运动结合在一起。电子的量子力学处理对于理解分子的化学反应、光学、磁学和其他性质是重要和关键的。更重要的是，这些新方法将允许研究人员研究更大的系统，如纳米材料。潜在的应用包括将光转化为电能的光伏材料，原子和分子在膜中的运动，以及同位素分离。科学目标是为10-200个原子组成的系统开发一种实用的方法，其中包括某些核或运动模式(量子化的振动、旋转)的核量子效应，同时它们与其余经典描述的核完全相互作用。借鉴薛定谔方程的量子轨道形式的思想，我们将发展一个基于轨道的理论框架，在更大的分子环境中选择性地包括NQE，将概念转化为计算机代码，并通过模拟加深我们对分子系统的理解，例如上面提到的那些展示同位素和其他NQE的分子系统。更广泛的教育目标是在理论、计算化学和高性能计算方面培训初级研究人员，通过正式的教学和合作项目促进实验同事使用计算化学工具，并为南卡罗来纳州的本科生机构提供计算化学工具的访问和培训。

In this project funded by the Chemical Theory, Models and Computational Methods program in the Division of Chemistry, Professor Sophya Garashchuk, at the University of South Carolina, Columbia, is developing new theoretical methods to analyze the dynamics of molecular motion. This method combines the microscopic behavior of electrons in molecules, treated by quantum mechanics with the motion of the nuclei of the atoms treated by classical mechanics, following that of Isaac Newton. The quantum-mechanical treatment of electrons is important and crucial to understand chemical reactivity, optical, magnetic and other properties of molecules. More importantly these new methods will allow researchers to investigate larger systems such as nanomaterials. Potential applications include photovoltaic materials that convert light to electricity, movement of atoms and molecules through membranes, and isotopic separation. The scientific goal is to develop a practical methodology for systems of 10-200 atoms, which incorporates Nuclear Quantum Effects (NQEs) for certain nuclei or modes of motion (quantized vibrations, rotations), while they fully interact with the remaining classically-described nuclei. Drawing on the ideas from the quantum trajectory formulation of the Schrodinger equation, we will develop a trajectory-based theoretical framework of including NQEs selectively within a larger molecular environment, transform the concepts into computer codes and through simulations advance our understanding of molecular systems, such as those mentioned above, known to exhibit isotope and other NQEs. Broader educational goals are to train junior researchers in theoretical, computational chemistry, and high performance computing, to facilitate use of computational chemistry tools by experimental colleagues through formal teaching and collaborative projects, and to provide access and training in computational chemistry tools for undergraduate institutions in South Carolina.