Efficient Implementation of A New and Accurate DFT Method

描述（由申请人提供）：密度泛函理论（DFT）可能是分子模拟中应用最广泛的量子化学方法，因为它能够准确有效地模拟各种分子系统。然而，它有一个主要的不足，即缺乏非动态相关性。因此，对于化学反应、自由基、激发态和电荷转移，它可能产生不可靠的结果。这些特性通常是基于生物的研究和开发的重点，只能通过基于量子力学的方法进行计算研究。在这个项目的第一阶段，我们为一种新的DFT方法开发了一种有效的自一致解决方案，称为实空间相关（RSC），以解决这一缺陷。此外，我们的RSC-DFT实现被证明是非常有效的，比以前的实现快100倍。我们的第一阶段结果表明，RSC不仅在标准的DFT测试用例中表现出色，而且还克服了DFT的一些已知故障。第二阶段项目的总体目标是使RSC可用于大多数DFT计算，包括计算基态和激发态的能量和梯度。我们还将进一步降低RSC的计算成本，使其与传统DFT一样高效。我们的开发将通过两个生物学应用得到验证，其中DFT已知给出较差的结果。最后，RSC将与我们的色散DFT实现相结合，统一的方法将代表DFT的实质性飞跃，使研究人员能够常规和可靠地研究分子系统，这在目前基于量子化学的技术中是不可能的。这也将使Q-Chem能够将其市场扩展到新的领域。

DESCRIPTION (provided by applicant): Density functional theory (DFT) is perhaps the most widely applied quantum chemistry method in molecular simulations due to its ability to accurately and efficiently model a wide range of molecular systems. Still, it has a major deficiency, namely the lack of nondynamic correlation. As a result, it can yield unreliable results for chemical reactions, radicals, excited states, and charge-transfers. These properties are very often the focus of biological-based research and development and can only be studied computationally with quantum mechanical based methods. In Phase I of this project, we developed an efficient self-consistent solution for a new DFT method called real-space correlation (RSC) that addresses this deficiency. In addition, our RSC-DFT implementation was shown to be very efficient, some 100 times faster than a prior implementation. Our Phase I results demonstrate that RSC not only excels in standard DFT test cases, but also overcomes some of DFT's known failures. The overall goal of this Phase II project is to make RSC available for the majority of DFT computations, including calculation of the energy and gradient for ground and excited electronic states. We will also reduce the computational cost of RSC even further such that it will be as efficient as conventional DFT. Our development will be validated through two applications of biological interest, where DFT is known to give poor results. Finally, RSC will be combined with our dispersion DFT implementation, , and the unified method will represent a substantial leap forward in DFT, allowing researchers to routinely and reliably study molecular systems that were heretofore not possible with current quantum chemistry based techniques. This will also allow Q-Chem to expand its market to new areas. PUBLIC HEALTH RELEVANCE: This project aims to implement a new DFT method in a computationally efficient manner. DFT is at the core of molecular modeling and is applied widely in biological research/development and in drug discovery. The improved DFT will significantly increase researchers' quality of work and extend the application scope of DFT.