Efficient Implementation of A New and Accurate DFT Method

一种新的、准确的 DFT 方法的高效实现

• 批准号: 7323188
• 负责人: JING KONG
• 金额: $ 10.43万
• 依托单位: Q-CHEM, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7323188
• 关键词: Algorithms; Arts; Benchmarking; Biochemistry; Biological; Biological Models; Charge; Chemicals; Computer software; Development; Discipline; Electronics; Equation; Evaluation; Foundations; Frequencies; Hydrogen Bonding; Hydrophobic Interactions; Lead; Methods; Modeling; Molecular; Molecular Biology; Motion; Phase; Procedures; Process; Property; Range; Reaction; Research; Resolution; Scheme; Science; Small Business Funding Mechanisms; Small Business Innovation Research Grant; Solutions; Standards of Weights and Measures; System; Techniques; Time; base; chemical reaction; concept; cost; density; design; energy density; human SMO protein; model development; novel; novel strategies; prevent; quantum chemistry; simulation; theories

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 some deficiencies in two major aspects of biological modeling: the barriers of chemical reactions (including charge transfer and hydrogen bonding) and the dispersion interaction prominent in hydrophobicinteractions. Recently, Axel Becke, one of the pioneers of DFT, and his co-workers, have proposed two conceptually novel functional models to overcome the deficiencies and their results have shown a great deal of potential. The model for the reaction barrier, namely real-space correlation (RSC), imposes a serious challenge to the current DFT numerical algorithms. The solution to the challenge is also a prerequisite to the efficient exploitation of the dispersion model. The RSC model requires the evaluation of Hartree-Fock (HF) exchange energy density at each grid point, which incurs prohibitively high computational cost. Further more, it contains a non-smooth correlation factor and an iterative solution to an auxiliary functional, preventing a self-consistent-field (SCF) solution. For this Phase I project, we propose to apply the resolution-of-identity technique to reduce the cost of the calculation of the HF-exchange energy density in the RSC model. We will show that the computational cost of the new algorithm will be reduced to the same level as the conventional DFT algorithms. We will also develop an analytical interpolation to the auxiliary functional and smoothen the correlation factor. All those developments will lead to a SCF solution of the RSC model, which is needed in just about every application of DFT. The new development will afford the general application of the new and accurate DFT method and enable its further development.

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。但在生物模拟的两个主要方面：化学反应的障碍（包括电荷转移和氢键）和疏水相互作用中突出的分散相互作用方面仍存在一些不足。最近，DFT的先驱之一阿克塞尔Becke和他的同事们提出了两个概念新颖的泛函模型来克服这些缺陷，他们的结果显示了很大的潜力。反应势垒模型，即实空间关联（RSC），对现有的DFT数值算法提出了严峻的挑战。挑战的解决方案也是有效利用分散模型的先决条件。RSC模型需要在每个网格点处评估Hartree-Fock（HF）交换能量密度，这导致过高的计算成本。此外，它包含了一个非光滑的相关因子和一个辅助泛函的迭代解，防止了自洽场（SCF）的解决方案。对于这个第一阶段的项目，我们建议应用分辨率的身份技术，以减少在RSC模型中的HF交换能量密度的计算成本。我们将表明，新算法的计算成本将降低到与传统DFT算法相同的水平。我们还将开发一个分析插值的辅助功能和平滑的相关因子。所有这些发展将导致RSC模型的SCF解决方案，这在DFT的几乎每一个应用中都需要。这一新的发展将为新的、精确的DFT方法的普遍应用提供条件，并使其得到进一步的发展。