Käser Silvan, Richardson Jeremy O, Meuwly Markus
Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
J Chem Theory Comput. 2025 Jul 8;21(13):6633-6643. doi: 10.1021/acs.jctc.5c00523. Epub 2025 Jun 20.
Accurate potential energy surfaces (PESs) are critical for predictive molecular simulations. However, obtaining a PES at the highest levels of quantum chemical accuracy, such as CCSD(T), becomes computationally infeasible as molecular size increases. This work presents CCSD(T)-quality PESs using data-efficient techniques based on transfer learning to obtain state-of-the-art accuracy at a fraction of the computational cost for systems that would otherwise be intractable. Most importantly, the framework for accurate molecular simulations pursued here extends beyond specific observables and follows a rational strategy to obtain highest-accuracy PESs, which can be used for applications to spectroscopy and other experiments. As rigorous tests of the PESs, semiclassical tunnelling splittings for tropolone and the (propiolic acid)-(formic acid) dimer (PFD) as well as anharmonic frequencies for tropolone were determined. For tropolone, all observables are in excellent agreement with the experiment using the high-level PES, whereas for PFD, the agreement is less good but still orders of magnitude better than previous calculations.
精确的势能面（PESs）对于预测性分子模拟至关重要。然而，随着分子尺寸的增加，以最高量子化学精度水平（如CCSD(T)）获得PES在计算上变得不可行。这项工作提出了基于迁移学习的数据高效技术来获得CCSD(T)质量的PESs，从而以一小部分计算成本获得最先进的精度，而对于其他方法难以处理的系统来说，这样的成本是可承受的。最重要的是，这里所追求的精确分子模拟框架超越了特定的可观测值，并遵循一种合理的策略来获得最高精度的PESs，可用于光谱学和其他实验应用。作为对PESs的严格测试，确定了托酚酮以及（丙炔酸）-（甲酸）二聚体（PFD）的半经典隧穿分裂以及托酚酮的非谐频率。对于托酚酮，使用高级PES时所有可观测值与实验结果都非常吻合，而对于PFD，吻合度稍差，但仍比先前的计算结果好几个数量级。
