Coupled cluster benchmarks of large noncovalent complexes: The L7 dataset as well as DNA-ellipticine and buckycatcher-fullerene
Coupled cluster benchmarks of large noncovalent complexes: The L7 dataset as well as DNA-ellipticine and buckycatcher-fullerene
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DOI：
10.1063/5.0042906
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发表时间：
2021-04-21
影响因子：
4.4
通讯作者：
Lao, Ka Un
中科院分区：
文献类型：
--
作者：
Ballesteros, Francisco;Dunivan, Shelbie;Lao, Ka Un
在这项工作中，使用基于二阶MOller-Plesset理论（MP2）标准形的焦点方法和基于局域对自然轨道方案的耦合团簇单，双，和微扰三重激发[CCSD（T）]外推到完全基组（CBS）极限。考虑到最近使用L7的局部自然轨道CCSD（T）和晕苯二聚体（C2 C2 PD）的经典CCSD（T）/CBS结果获得的值的一致性，这项工作可以增加置信度。因此，这些结果可以被认为将CCSD（T）/CBS结合基准推向了百原子尺度。两种最先进的方法，CCSD（T）和固定节点扩散蒙特卡罗之间的差异是实质性的，L7中的C2 C2 PD、DNA-椭圆树花碱和巴基catcher-C-60的差异分别为至少2.0（类似于10%）、1.9（类似于5%）和10.3 kcal/mol（类似于25%）。对于大的非共价复合物，这种高于“化学准确性”的相当大的差异表明，获得小分子以外的系统的基准结合相互作用是多么具有挑战性，尽管三个最新的密度泛函PBE 0 +D4、omega B 97 M-V和B 97 M-V与CCSD（T）在这些大系统中的一致性更好。除了报告这些值之外，还首次在大型非共价复合物中测试了Hartree-Fock和MP2相关能的不同基组和各种CBS外推参数，目标是提供一些关于最佳成本效益路线的指示，以接近CBS限制，而不会造成实质性损失质量。
In this work, benchmark binding energies for dispersion-bound complexes in the L7 dataset, the DNA-ellipticine intercalation complex, and the buckycatcher-C-60 complex with 120 heavy atoms using a focal-point method based on the canonical form of second-order MOller-Plesset theory (MP2) and the domain based local pair natural orbital scheme for the coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] extrapolated to the complete basis set (CBS) limit are reported. This work allows for increased confidence given the agreement with respect to values recently obtained using the local natural orbital CCSD(T) for L7 and the canonical CCSD(T)/CBS result for the coronene dimer (C2C2PD). Therefore, these results can be considered pushing the CCSD(T)/CBS binding benchmark to the hundred-atom scale. The disagreements between the two state-of-the-art methods, CCSD(T) and fixed-node diffusion Monte Carlo, are substantial with at least 2.0 (similar to 10%), 1.9 (similar to 5%), and 10.3 kcal/mol (similar to 25%) differences for C2C2PD in L7, DNA-ellipticine, and buckycatcher-C-60, respectively. Such sizable discrepancy above "chemical accuracy" for large noncovalent complexes indicates how challenging it is to obtain benchmark binding interactions for systems beyond small molecules, although the three up-to-date density functionals, PBE0+D4, omega B97M-V, and B97M-V, agree better with CCSD(T) for these large systems. In addition to reporting these values, different basis sets and various CBS extrapolation parameters for Hartree-Fock and MP2 correlation energies were tested for the first time in large noncovalent complexes with the goal of providing some indications toward optimal cost effective routes to approach the CBS limit without substantial loss in quality.