Efficient double hybrid density functional theory algorithms for conformational a

描述(申请人提供)：Q-Chem是一个最先进的商业计算量子化学程序，已帮助数万用户对包括生物、化学和材料科学在内的广泛学科的分子过程进行建模。在量子化学中，密度泛函理论(DFT)和二阶Moller-Plesset理论(MP2)已经被广泛地应用于分子力学力场的发展以及蛋白质-配体结合亲和力和酶反应自由能的混合量子力学模拟中，尽管它们的精度和计算成本有限。为了解决这些局限性，我们提出了用于计算构象能和结合能的双杂化密度泛函。具体地说，我们的目标是：(1)进一步提高在我们的第一阶段研究中开发的短程MP2(SR-MP2)方法的计算效率，并证明它产生了前所未有的精度和效率；(2)在我们的SR-MP2之上建立新的双杂交密度泛函，以进一步扩展其适用性；以及(3)展示SR-MP2和相关的新DHDF在化学和生物问题中的使用。这项第二阶段研究产生的新工具将超过现有的DFT和MP2方法，并在降低计算成本的情况下提高精度，打开新的应用程序，以及改进化学、生化和生物医学研究中的现有应用程序。这项工作将进一步巩固Q-Chem作为分子建模软件市场全球领导者的地位，使我们的程序成为模拟大型、复杂化学/生物系统的最有效和最可靠的计算量子化学程序包。

DESCRIPTION (provided by applicant): Q-Chem is a state-of-the-art commercial computational quantum chemistry program that has aided tens of thousands users in their modeling of molecular processes in a wide range of disciplines, including biology, chemistry, and materials science. In quantum chemistry, density functional theory (DFT) and second order Moller-Plesset theory (MP2) are already heavily used in the development of molecular mechanics force fields and in the hybrid quantum mechanical molecular mechanical simulations of protein-ligand binding affinities and enzymatic reaction free energies, despite their accuracy and computational cost limitations. To address these limitations, we seek to advance double hybrid density functionals (DHDFs) for computing conformational and binding energies. Specifically, we aim to: (1) Further enhance the computational efficiency of the short range MP2 (SR-MP2) method, which was developed in our Phase I research and demonstrated to yield unprecedented accuracy and efficiency; (2) Build new double hybrid density functionals on top of our SR-MP2 in order to further extend its applicability; and (3) Demonstrate the use of both SR-MP2 and associated new DHDFs in chemical and biological problems. The new tools coming out of this Phase II research will outperform existing DFT and MP2 methods, and yield improved accuracy with reduced computational cost, opening new applications as well as improving existing ones in chemical, biochemical and biomedical research. This work will further strengthen Q-Chem's position as a global leader in the molecular modeling software market, making our program the most efficient and reliable computational quantum chemistry package for simulating large, complex chemical/biological systems.