Real-time path integral methodology for condensed-phase quantum dynamics

伊利诺伊大学的Nancy Makri获得了化学系化学理论、模型和计算方法项目的奖励，她开发了精确的计算方法，用于研究化学和生物系统中的质子、电子和能量转移过程。这些转移过程在生物体以及能源生产和储存中起着至关重要的作用。涉及光粒子和能量转移的反应是由量子力学效应主导的。这些效应是基于基本粒子（质子、电子等）也表现为波的想法，因此，它们的结构和与其他物质的相互作用有数学解释。量子力学效应不能用经典的处理方法正确地建模。Makri教授和她的同事设计了新的理论和计算方法来规避这个问题；他们的方法产生了更精确和有效的仿真算法。由此产生的软件可以帮助解释实验结果。新软件通过增强经典模拟提供的可视化能力来增强课堂学习体验。该项目为研究生和博士后研究人员提供了接受量子动力学培训的机会，掌握最先进的理论思想和模拟工具。量子力学的传统公式是基于波函数的，这需要阵列存储，远远超过当前计算机的能力。Makri的方法基于全量子力学路径积分公式，而数千个溶剂或蛋白质原子对感兴趣的量子系统动力学的影响是通过经典轨迹捕获的。Makri小组开发的实时路径积分方法不含假设和不受控制的近似，结果精度很高。在用谐波浴来描述环境影响的情况下，Makri的工作可能会将仿真算法的功能扩展到具有长记忆和多状态的系统。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nancy Makri of the University of Illinois is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to develop accurate computational methods for studying proton, electron, and energy transfer processes in chemical and biological systems. These transfer processes play a vital role in living organisms, as well as in energy production and storage. Reactions involving light particles and energy transfer are dominated by quantum mechanical effects. These effects are based on the idea that elementary particles (protons, electrons, etc.) also behave as waves and thus, have mathematical interpretations of their structure and interactions with other matter. Quantum mechanical effects cannot be modeled correctly using classical treatments. Professor Makri and her coworkers design new theoretical and computational approaches for circumventing this problem; their approaches produce more accurate and efficient simulation algorithms. The resulting software may aid in the interpretation of experimental results. The new software enhances the learning experience in the classroom by augmenting the visualization ability offered by classical simulations. The project offers graduate students and a postdoctoral researchers opportunities to receive training in quantum dynamics, mastering state-of-the-art theoretical ideas and simulation tools. The traditional formulation of quantum mechanics is based on wave functions, which require array storage that far exceeds current computer capabilities. Makri’s approach is based on the fully quantum mechanical path integral formulation while the influence of thousands of solvent or protein atoms on the dynamics of the quantum system of interest is captured through classical trajectories. The real-time path integral methods developed by Makri’s group are free of assumptions and uncontrolled approximations, leading to highly accurate results. In the case where the effects of the environment are described in terms of a harmonic bath, Makri’s work may extend the capabilities of simulation algorithms to systems with long memory and multiple states.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.