Time-dependent density functional theory for open quantum systems

哈佛大学的Alan Aspuru-Guzik获得了化学系化学理论、模型和计算方法项目的一项奖励，以开发开放系统的时间依赖密度泛函（TDDFT）方法。 该奖项由材料研究部的凝聚态物质和材料理论计划共同资助。 需要新的理论方法来解释化学系统中能量和电子传递的时间尺度，如光合作用和有机光合作用。 为了允许耗散和弛豫，必须允许量子系统与无限大的浴池交换能量。 在这个项目中，Aspuru-Guzik和他的同事基于基本物理而不是输入参数，开发了分子中耗散电子动力学的第一原理理论。 该项目与以前的工作不同的是电子系统模型的详细程度。这些新方法以严格的方式处理组合系统。 与这些理论一起开发的计算机模拟代码被应用于激子传输等化学问题。这项研究允许研究与植物和有机材料制成的太阳能电池捕光相关的系统的量子动力学。 我们开发的方法可以从原子论的角度回答有关这些过程细节的基本问题。一群不同的研究人员参与了这个项目。该小组开发的程序代码将被纳入公开的开源量子化学软件包中。 PI还参与了一项名为“清洁能源项目”的分布式工作;来自世界各地的数千名计算机用户捐赠了他们闲置的计算能力，以寻找太阳能电池的新材料。

Alan Aspuru-Guzik of Harvard University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to develop time dependent density functional (TDDFT) methods for open systems. This award is co-funded by the Condensed Matter and Materials Theory program in the Division of Materials Research. New theoretical methods are required to explain the timescales of energy and electron transport in chemical systems, such as photosynthesis and organic photovoltaics. In order to allow for dissipation and relaxation, the quantum system must be allowed to exchange energy with an infinite bath. In this project, Aspuru-Guzik and his coworkers develop first-principles theories of dissipative electronic dynamics in molecules based on basic physics, rather than input parameters. The project differs from previous work by the level of detail provided for the model of the electronic system. These new approaches treat the combined system in a rigorous manner. Computer simulation codes developed alongside these theories are applied to chemical problems like excitonic transport. This research allows for the study of quantum dynamics of systems of relevance to light harvesting by plants and solar cells made of organic materials. The methods we develop could answer fundamental questions about the details of these processes from an atomistic perspective. A diverse group of researchers are engaged in this project. The program codes developed by the group will be incorporated into publicly available open-source quantum chemistry packages. The PI is also involved in a distributed effort called "The Clean Energy Project"; thousands of computer users from around the world donate their idle computing power to search for new materials for solar cells.