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Efficient double hybrid density functional theory algorithms for conformational a

构象α的高效双杂化密度泛函理论算法

基本信息

批准号：
8123785
负责人：
JING KONG
金额：
$ 10.12万
依托单位：
Q-CHEM, INC.
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-15 至 2012-09-14
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Double hybrid (DH) density functionals are one of the most promising new developments in quantum mechanical methods for simulating biomolecules. DH functionals have been reported to yield much more accurate intermolecular interaction energies than previous generation functionals. They are therefore on the threshold of becoming widely used. However, there are still practical obstacles blocking widespread use of DH functionals, apart from lack of familiarity to users. This SBIR proposal aims to embrace the opportunity of greater accuracy offered by the DH approach by directly addressing the key known limitations. These limitations and our proposed remedies are as follows. (i) DH functionals are more computationally expensive to evaluate than conventional functionals because the cost scales as the 5th power, rather than the 3rd power of molecular size. We will implement and benchmark a novel 3rd order method for evaluating the DH energy without explicit two-electron integrals. The computational savings for biophysically useful accuracy will be assessed on conformational relative energies. (ii) DH functionals require larger atomic orbital basis sets to yield converged relative energies, but doubling the basis requires 16 times more computation. We will significantly ameliorate this slow convergence by augmenting the basis to explicitly include interelectronic coordinates, via F12 techniques that have proven successful for wave function methods. This first use of F12 methods to evaluate the DH energy will be benchmarked to assess the reduction in basis set size that is possible without sacrificing accuracy for conformational energies and intermolecular interactions. PUBLIC HEALTH RELEVANCE: 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.

描述（由申请人提供）：双杂化（DH）密度泛函是模拟生物分子的量子力学方法中最有前途的新发展之一。据报道，DH 泛函可产生比前一代泛函更准确的分子间相互作用能。因此，它们即将被广泛使用。然而，除了用户不熟悉之外，DH 函数的广泛使用仍然存在实际障碍。该 SBIR 提案旨在通过直接解决关键的已知限制，抓住 DH 方法提供的更高准确性的机会。这些限制和我们建议的补救措施如下。 (i) DH 泛函的评估比传统泛函的计算成本更高，因为成本按分子大小的 5 次方而不是 3 次方缩放。我们将实施一种新颖的三阶方法并对其进行基准测试，用于在没有显式二电子积分的情况下评估 DH 能量。生物物理学上有用的准确性的计算节省将根据构象相对能量进行评估。 (ii) DH 泛函需要更大的原子轨道基组来产生收敛的相对能量，但基数加倍需要 16 倍的计算量。我们将通过在波函数方法中已被证明是成功的 F12 技术，通过增强基础以明确包含电子间坐标，从而显着改善这种缓慢的收敛。首次使用 F12 方法评估 DH 能量将进行基准测试，以评估在不牺牲构象能量和分子间相互作用的准确性的情况下可能减少的基组大小。公共卫生相关性：以计算有效的方式实施新的 DFT 方法。 DFT 是分子建模的核心，广泛应用于生物研究/开发和药物发现。改进后的DFT将显着提高研究人员的工作质量并扩展DFT的应用范围。