论文标题
（H2O）20异构体的能量学通过F12规范和局部耦合群集方法
Energetics of (H2O)20 Isomers by means of F12 Canonical and Localized Coupled Cluster Methods
论文作者
论文摘要
我们考虑了与（H2O）20一样大的水簇分离能的组合PNO-F12方法的性能，与规范CCSD（T）/CBS参考值相比，通过MP2校正后的N体分分解获得。我们发现，PNO-LCCSD（t）-F12B方法的“紧密”截止方法通常能够将规范CCSD（T）相互作用能量繁殖到〜0.25％以内，同源能量且同源能量为〜1.5％，而仅需要一小部分规范计算成本。但是，基础集合模式和反平衡校正的效果比规范计算更不稳定，这突出了对密切相关系统上规范基准的需求。
We consider the performance of combined PNO-F12 approaches for the dissociation energy of water clusters as large as (H2O)20 by comparison to canonical CCSD(T)/CBS reference values obtained through n-body decomposition of post-MP2 corrections. We find that PNO-LCCSD(T)-F12b approaches with "Tight" cutoffs are generally capable of reproducing canonical CCSD(T) interaction energies to within ~0.25% and isomerization energies to ~1.5%, while requiring only a fraction of the canonical computational cost. However, basis set convergence patterns and effect of counterpoise corrections are more erratic than for canonical calculations, highlighting the need for canonical benchmarks on closely related systems.
