Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA.
J Comput Chem. 2011 Feb;32(3):453-62. doi: 10.1002/jcc.21634. Epub 2010 Aug 20.
The recently introduced adaptive force matching (AFM) method is used to develop a significantly improved pair-wise nonpolarizable potential for water. A rigid version of the potential is also presented to enable larger time steps for biological simulations. In this work, it is demonstrated that the AFM method can be used to systematically assess the importance of each functional term during the construction of a force field. For a water potential, it is established that a single off-atom charge center (M) in the plane of water outperforms two out-of-plane charge sites for reproducing intermolecular forces. The four-site pair-wise nonpolarizable force field developed in this work rivals some of the most sophisticated polarizable models in terms of reproducing accurate ab initio forces. The force fields are parameterized to perform best in the temperature range from 0 to 40°C. Equilibrium and dynamical properties calculated with the flexible and rigid force fields are in good agreement with experimental results. For the flexible model, the agreement improves when path integral simulation is performed. These force fields provide high-quality results at a very low computational cost and are thus well suited to atomistic scale biological simulations. The AFM method provides a mechanism for selecting important terms in force field expressions and is a very promising tool for producing accurate force fields in condensed phases.
最近引入的自适应力匹配 (AFM) 方法被用于开发一种显著改进的、针对非极性相互作用的两两可极化势能。还提出了一种刚性版本的势能，以支持生物模拟中更大的时间步长。在这项工作中，证明了 AFM 方法可用于在构建力场时系统地评估每个功能项的重要性。对于水的势能，确定在水分子平面上的单个离域电荷中心 (M) 比两个离域电荷位点更能重现分子间力。在这项工作中开发的四位点两两非极化力场在重现准确从头算力方面可与一些最复杂的极化模型相媲美。力场参数化以在 0 到 40°C 的温度范围内表现最佳。使用柔性和刚性力场计算的平衡和动力学性质与实验结果吻合良好。对于柔性模型，当进行路径积分模拟时，吻合度会提高。这些力场以非常低的计算成本提供高质量的结果，因此非常适合原子尺度的生物模拟。AFM 方法提供了一种在力场表达式中选择重要项的机制，是在凝聚相产生准确力场的很有前途的工具。
