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）：密度功能理论（DFT）可能是分子模拟中最广泛应用的量子化学方法，因为它能够准确有效地建模广泛的分子系统。尽管如此，它仍在生物建模的两个主要方面存在一些缺陷：化学反应的障碍（包括电荷转移和氢键）以及在疏水性互比中突出的分散相互作用。最近，DFT的先驱之一Axel Becke提出了两个概念上新型功能模型来克服缺陷，他们的结果表现出了很大的潜力。反应屏障的模型，即真实空间相关性（RSC），对当前的DFT数值算法构成了严重的挑战。解决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评估Hartree-Fock（HF）交换能量密度，这会产生高度高的计算成本。此外，它包含非平滑相关因子和辅助功能的迭代解决方案，以防止自稳态场（SCF）解决方案。对于此阶段I项目，我们建议应用标识技术以降低RSC模型中HF-交换能量密度的计算成本。我们将证明，新算法的计算成本将降低到与常规DFT算法相同的水平。我们还将为辅助功能开发一个分析插值并使相关因子平滑。所有这些开发将导致RSC模型的SCF解决方案，这在DFT的每一个应用中都需要。新开发将提供新的和准确的DFT方法的一般应用，并实现其进一步的发展。