Efficient Implementation of A New and Accurate DFT Method

描述(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，因为它能够准确和有效地模拟广泛的分子系统。尽管如此，它仍有一个重大缺陷，即缺乏非动态相关性。因此，它可能会对化学反应、自由基、激发态和电荷转移产生不可靠的结果。这些性质往往是基于生物的研究和开发的重点，只能用基于量子力学的方法通过计算来研究。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洽解决方案，称为实空间相关(RSC)，以解决这一不足。此外，我们的RSC-DFT实现被证明是非常有效的，比以前的实现快了大约100倍。我们的第一阶段结果表明，RSC不仅在标准DFT测试用例中表现出色，而且还克服了DFT的一些已知故障。这个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电子态的能量和梯度。我们还将进一步降低RSC的计算成本，使其与传统的DFT一样高效。我们的开发将通过两个具有生物学意义的应用来验证，在这两个应用中，DFT的结果很差。最后，RSC将与我们的色散DFT实施相结合，而统一的方法将代表着DFT的重大飞跃，使研究人员能够常规而可靠地研究分子体系，而这些分子体系迄今无法使用当前基于量子化学的技术进行研究。这也将使Q-Chem能够将其市场扩展到新的领域。 公共卫生相关性：该项目旨在以计算高效的方式实施一种新的DFT方法。离散傅立叶变换是分子模拟的核心，在生物研究和药物开发中得到了广泛的应用。改进后的离散傅里叶变换将显著提高研究人员的工作质量，扩大离散傅里叶变换的应用范围。

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.