Density Functional Theory for van der Waals Interactions

描述（由申请人提供）：Q-Chem是一个最先进的商业量子化学程序，用于模拟包括生物学、化学和材料科学在内的广泛学科的原子和分子过程。在量子化学方法中，密度泛函理论（DFT）可能是最广泛使用的，特别是在分子生物学中，由于其能够以合理的计算成本准确地模拟各种分子系统。尽管如此，DFT不包括色散相关效应，或货车的德瓦尔斯相互作用，这起着至关重要的作用，在分子系统的整体构象的测定，因此，是不可缺少的DNA和蛋白质，分子识别，包装的晶体等的研究，我们建议增加的能力，准确地模拟DFT框架内的色散效应。具体来说，我们将开发和实施自洽场（SCF）和梯度解决方案，最近提出的色散模型，这已被证明是非常准确的R-6和高阶项的色散系数，没有经验参数，非常准确的结合能弱结合系统和相对构象能量与阻尼项只有两个经验参数。目前该模型由于缺乏自洽场和梯度算法，只能用于计算分子能量，无法应用于实际研究。该模型的成功开发和实现将为真实的化学和生物问题带来更可靠的DFT解决方案。 公共卫生相关性：该项目旨在开发和实施一种非常准确的DFT方法。密度泛函理论（DFT）是分子模拟的核心，广泛应用于生物学研究和药物开发中。改进后的DFT将显著提高研究人员的工作质量，扩大DFT的应用范围。

DESCRIPTION (provided by applicant): Q-Chem is a state-of-the-art commercial quantum chemistry program that is used to model atomic and molecular processes over a wide range of disciplines, including biology, chemistry, and materials science. Among the quantum chemistry methods, density functional theory (DFT) is perhaps the most widely used, especially in molecular biology, due to its ability to accurately model a wide range of molecular systems with reasonable computational cost. Still, DFT does not include the dispersion correlation effect, or van der Waals interaction, which plays a critical role in the determination of the overall conformations of molecular systems and accordingly, is indispensable in the study of DNA and proteins, molecular recognition, the packing of crystals, etc. We propose to add the ability to accurately model dispersion effects within the DFT framework. Specifically, we will develop and implement self-consistent-field (SCF) and gradient solutions to a recently proposed dispersion model, which has been shown to yield very accurate dispersion coefficients for R-6 and higher order terms with no empirical parameters, and very accurate binding energies for weakly bound systems and relative conformation energies with a damping term of just two empirical parameters. Currently this model cannot be applied in practical studies because it can only be used to calculate molecular energies due to the lack of SCF and gradient algorithms. The successful development and implementation of the model will lead to much more reliable DFT solutions for real chemical and biological problems. PUBLIC HEALTH RELEVANCE: This project aims to develop and implement a very accurate DFT method. 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.