Mihm Tina N, Yang Bingdi, Shepherd James J
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States.
J Chem Theory Comput. 2021 May 11;17(5):2752-2758. doi: 10.1021/acs.jctc.0c01171. Epub 2021 Apr 8.
Recent calculations using coupled cluster on solids have raised the discussion of using a power law to fit the correlation energy when extrapolating to the thermodynamic limit, an approach which differs from the more commonly used power law, which is, for example, often used by quantum Monte Carlo methods. In this paper, we present one way to reconcile these viewpoints. Coupled cluster doubles calculations were performed on uniform electron gases reaching system sizes of 922 electrons for an extremely wide range of densities (0.1 < < 100.0) to study how the correlation energy approaches the thermodynamic limit. The data were corrected for the basis set incompleteness error and use a selected twist angle approach to mitigate the finite size error from shell filling effects. Analyzing these data, we initially find that a power law of appears to fit the data better than a power law in the large system size limit. However, we provide an analysis of the transition structure factor showing that still applies to large system sizes and that the apparent power law occurs only at low .
最近在固体上使用耦合簇方法进行的计算引发了关于在外推到热力学极限时使用幂律来拟合相关能的讨论，这种方法不同于更常用的幂律，例如量子蒙特卡罗方法经常使用的幂律。在本文中，我们提出了一种调和这些观点的方法。对均匀电子气进行了耦合簇双激发计算，系统大小达到922个电子，密度范围极广（0.1 << 100.0），以研究相关能如何趋近于热力学极限。对数据进行了基组不完备误差校正，并采用选定的扭曲角方法来减轻壳层填充效应引起的有限尺寸误差。分析这些数据时，我们最初发现，在大系统尺寸极限下，幂律似乎比幂律更能拟合数据。然而，我们对跃迁结构因子进行了分析，结果表明幂律仍然适用于大系统尺寸，而表观的幂律仅在低密度时出现。
