Powell Samuel R, Surjuse Kshitijkumar A, Gaudel Bimal, Valeev Edward F
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060, United States.
J Chem Theory Comput. 2025 Sep 23;21(18):8833-8842. doi: 10.1021/acs.jctc.5c00971. Epub 2025 Sep 10.
The Slater-type F12 geminal length scales originally tuned for the second-order Mo̷ller-Plesset F12 method are too large for higher-order F12 methods formulated using the SP (diagonal fixed-coefficient spin-adapted) F12 ansatz. The new geminal parameters reported herein reduce the basis set incompleteness errors (BSIEs) of absolute coupled-cluster singles and doubles F12 correlation energies by a significant─and increase with the cardinal number of the basis─margin. The effect of geminal reoptimization is especially pronounced for the cc-pVZ-F12 basis sets (specifically designed for use with F12 methods) relative to their conventional aug-cc-pVZ counterparts. The BSIEs of relative energies are less affected, but substantial reductions can be obtained, especially for atomization energies and ionization potentials with the cc-pVZ-F12 basis sets. The new geminal parameters are therefore recommended for all applications of high-order F12 methods, such as coupled-cluster F12 methods and transcorrelated F12 methods.
最初为二阶莫勒-普列斯特定理F12方法调整的斯莱特型F12双原子长度标度，对于使用SP（对角固定系数自旋适应）F12假设公式化的高阶F12方法而言太大。本文报道的新双原子参数显著降低了绝对耦合簇单双激发F12相关能的基组不完备误差（BSIEs），并且随着基组基数增加而增大。相对于传统的aug-cc-pVZ基组，双原子重新优化的效果在cc-pVZ-F12基组（专门为与F12方法一起使用而设计）中尤为明显。相对能量的BSIEs受影响较小，但仍可大幅降低，特别是对于使用cc-pVZ-F12基组的原子化能和电离势。因此，新的双原子参数推荐用于高阶F12方法的所有应用，如耦合簇F12方法和超相关F12方法。
