Otero-de-la-Roza A, DiLabio Gino A
Department of Chemistry and ‡Faculty of Management, University of British Columbia, Okanagan , 3247 University Way, Kelowna, British Columbia, Canada V1V 1V7.
J Chem Theory Comput. 2017 Aug 8;13(8):3505-3524. doi: 10.1021/acs.jctc.7b00300. Epub 2017 Jul 21.
Recent progress in the accurate calculation of noncovalent interactions has enabled density-functional theory (DFT) to model systems relevant in biological and supramolecular chemistry. The application of DFT methods using atom-centered Gaussian basis sets to large systems is limited by the number of basis functions required to accurately model thermochemistry and, in particular, weak intermolecular interactions. Basis set incompleteness error (BSIE) arising from the use of incomplete basis sets leads to erroneous intermolecular energies, bond dissociation energies, and structures. In this article, we develop a correction for BSIE in DFT calculations using basis set incompleteness potentials (BSIP). BSIPs are atom-based one-electron potentials (ACPs) with the same functional form as effective core potentials (ECP) that are designed to correct the effects of BSIE in properties that are linear mappings of the energy. We present a systematic way of developing general, error-correcting ACPs and apply this technique to generate BSIPs for eight common elements in organic and biological systems (H, C, N, O, F, P, S, and Cl). Two BSIPs were optimized for use with the scaled MINI (MINIs) and MINIs(d) basis sets and were designed to correct for the impacts of BSIE on noncovalent binding energies and intra/intermolecular geometries. BSIPs developed for use with 6-31G*, pc-1, and 6-31+G** basis sets also correct for the effects of BSIE on bond dissociation energies, which enables the study of chemical reactions in very large systems. BSIPs can be used with any density functional in any electronic structure program that implements ECPs. Our BSIPs add very little to the computational cost provided an efficient ECP implementation is used. Our results support the use of BLYP-D3/MINIs-BSIP as a computationally inexpensive and more accurate alternative to other approaches (e.g., B3LYP/6-31G* and BP86/6-31G*) in protein and supramolecular structural studies.
非共价相互作用精确计算方面的最新进展使密度泛函理论（DFT）能够对生物化学和超分子化学中的相关体系进行建模。使用以原子为中心的高斯基组的DFT方法在应用于大型体系时，受到精确模拟热化学所需基函数数量的限制，尤其是在模拟弱分子间相互作用时。使用不完整基组产生的基组不完备误差（BSIE）会导致分子间能量、键解离能和结构出现错误。在本文中，我们利用基组不完备势（BSIP）对DFT计算中的BSIE进行校正。BSIP是基于原子的单电子势（ACP），其函数形式与有效核势（ECP）相同，旨在校正BSIE对作为能量线性映射的性质的影响。我们提出了一种开发通用误差校正ACP的系统方法，并将该技术应用于生成有机和生物体系中八种常见元素（H、C、N、O、F、P、S和Cl）的BSIP。针对缩放后的MINI（MINIs）和MINIs(d)基组优化了两种BSIP，旨在校正BSIE对非共价结合能和分子内/分子间几何结构的影响。为与6-31G*、pc-1和6-31+G*基组配合使用而开发的BSIP还能校正BSIE对键解离能的影响，从而能够研究非常大体系中的化学反应。BSIP可与任何实现ECP的电子结构程序中的任何密度泛函一起使用。只要使用高效的ECP实现，我们的BSIP对计算成本的增加微乎其微。我们的结果支持在蛋白质和超分子结构研究中，将BLYP-D3/MINIs-BSIP作为一种计算成本低且比其他方法（如B3LYP/6-31G和BP86/6-31G*）更准确的替代方法。
