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arXiv 2008.02057physics.chem-ph
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大体系的精确远距对修正分子内散射局域相关法

The Cluster-in-Molecule Local Correlation Method with an Accurate Distant Pair Correction for Large Systems

Zhigang Ni, Yang Guo, Frank Neese, Wei Li, Shuhua Li

摘要:

提出了一种精确修正远距对相关能量的分子团簇(CIM)局域相关方法。对于大系统,远距对关联能的加入对于精确预测绝对关联能和相对关联能是必不可少的。在这里,我们提出了一个简单而有效的计划,用于评估远对相关能量校正。这些修正可以很容易地从团簇的电子相关计算中提取出来,几乎不需要额外的努力。基准实验表明,改进的CIM方法可以恢复传统相关能量的99.97%以上。通过将CIM方法与基于区域的局域对自然轨道(DLPNO)局域相关方法相结合,我们在CIM-DLPNO-CCSD(T)水平上对8个弱结合复合物(大小从200到1027个原子)进行了精确的结合能计算.以这些结果为参考数据,对其他电子相关方法和几种密度泛函方法在大体系中的准确性和适用性进行了评价。

英文摘要:

The cluster-in-molecule (CIM) local correlation approach with an accurate distant pair correlation energy correction is presented. For large systems, the inclusion of distant pair correlation energies is essential for the accurate predictions of absolute correlation energies and relative energies. Here we propose a simple and efficient scheme for evaluating the distant pair correlation energy correction. The corrections can be readily extracted from electron correlation calculations of clusters with almost no additional effort. Benchmark calculations show that the improved CIM approach can recover more than 99.97% of the conventional correlation energy. By combining the CIM approach with the domain based local pair natural orbital (DLPNO) local correlation approach, we have provided accurate binding energies at the CIM-DLPNO-CCSD(T) level for a test set consisting of eight weakly bound complexes ranging in size from 200 to 1027 atoms. With these results as the reference data, the accuracy and applicability of other electron correlation methods and a few density functional methods for large systems have been assessed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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