准确预测核磁共振屏蔽常数：迈向 CCSD(T)完全基组极限的精度。

Accurate prediction of nuclear magnetic resonance shielding constants: towards the accuracy of CCSD(T) complete basis set limit.

机构信息

State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.

出版信息

J Chem Phys. 2013 Mar 28;138(12):124113. doi: 10.1063/1.4796485.

DOI:10.1063/1.4796485

PMID:23556715

Abstract

In this work, we have calculated the nuclear magnetic resonance (NMR) shielding constants for 42 molecules at the levels of second order Mo̸ller-Plesset perturbation (MP2) and coupled-cluster singles and doubles model augmented by perturbative corrections for triple excitations CCSD(T). Basis set extrapolations to the complete basis set (CBS) limit have been performed. A focal-point analysis method for magnetic parameters was proposed here, which adds the [σ(e)(CCSD(T)) - σ(e)(MP2)] difference to the MP2∕CBS number to approximate the corresponding CCSD(T)∕CBS value. Systematical comparison has demonstrated the usefulness of this FPA-M∕CBS scheme.

摘要

在这项工作中，我们在二阶 Møller-Plesset 微扰 (MP2) 和耦合簇单双加缀饰三电子项的修正(C C S D ( T ))水平上计算了 42 个分子的核磁共振 (NMR) 屏蔽常数。我们进行了基组外推到完全基组 (C B S )极限的计算。本文提出了一种用于磁参数的焦点分析方法，该方法将[σ(e)(C C S D ( T )) - σ(e)(MP2)]差值添加到 MP2∕CBS 数值上，以近似相应的 C C S D ( T )∕CBS 值。系统比较表明了这种 FPA-M∕CBS 方案的有用性。