Dobrautz Werner, Cohen Aron J, Alavi Ali, Giner Emmanuel
Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.
Laboratoire de Chimie Théorique, Sorbonne Université and CNRS, F-75005 Paris, France.
J Chem Phys. 2022 Jun 21;156(23):234108. doi: 10.1063/5.0088981.
In this work, we investigate the performance of a recently proposed transcorrelated (TC) approach based on a single-parameter correlation factor [E. Giner, J. Chem. Phys. 154, 084119 (2021)] for systems involving more than two electrons. The benefit of such an approach relies on its simplicity as efficient numerical-analytical schemes can be set up to compute the two- and three-body integrals occurring in the effective TC Hamiltonian. To obtain accurate ground state energies within a given basis set, the present TC scheme is coupled to the recently proposed TC-full configuration interaction quantum Monte Carlo method [Cohen et al., J. Chem. Phys. 151, 061101 (2019)]. We report ground state total energies on the Li-Ne series, together with their first cations, computed with increasingly large basis sets and compare to more elaborate correlation factors involving electron-electron-nucleus coordinates. Numerical results on the Li-Ne ionization potentials show that the use of the single-parameter correlation factor brings on average only a slightly lower accuracy (1.2 mH) in a triple-zeta quality basis set with respect to a more sophisticated correlation factor. However, already using a quadruple-zeta quality basis set yields results within chemical accuracy to complete basis set limit results when using this novel single-parameter correlation factor. Calculations on the HO, CH, and FH molecules show that a similar precision can be obtained within a triple-zeta quality basis set for the atomization energies of molecular systems.
在这项工作中，我们研究了一种最近提出的基于单参数关联因子的转相关（TC）方法[E. Giner，《化学物理杂志》154，084119（2021）]在涉及两个以上电子的系统中的性能。这种方法的优点在于其简单性，因为可以建立有效的数值分析方案来计算有效TC哈密顿量中出现的两体和三体积分。为了在给定基组内获得精确的基态能量，当前的TC方案与最近提出的TC-全组态相互作用量子蒙特卡罗方法[Cohen等人，《化学物理杂志》151，061101（2019）]相结合。我们报告了使用越来越大的基组计算得到的Li-Ne系列及其第一阳离子的基态总能量，并与涉及电子-电子-核坐标的更精细的关联因子进行比较。Li-Ne电离势的数值结果表明，在三重ζ质量基组中，相对于更复杂的关联因子，使用单参数关联因子平均仅带来略低的精度（1.2 mH）。然而，当使用这种新颖的单参数关联因子时，已经使用四重ζ质量基组就能在化学精度范围内得到结果，直至完全基组极限结果。对HO、CH和FH分子的计算表明，对于分子体系的原子化能，在三重ζ质量基组内可以获得类似的精度。
