Duarte Ramos Matos Guilherme, Calabrò Gaetano, Mobley David L
Department of Chemistry , University of California , Irvine , California 92697 , United States.
OpenEye Scientific Software , Santa Fe , New Mexico 87508 , United States.
J Chem Theory Comput. 2019 May 14;15(5):3066-3074. doi: 10.1021/acs.jctc.8b01029. Epub 2019 Apr 15.
Molecular simulations begin with an underlying energy model or force field and from this can predict diverse physical properties. However, force fields were often developed with relatively limited data sets, yet accuracy for diverse properties across a broad chemical space is desirable; therefore, tests of such accuracy are particularly important. Here, to this end, we calculated 237 infinite dilution activity coefficients (IDACs), comparing with experimental values from NIST's ThermoML database. We found that calculated IDAC values correlate strongly with experiment (Pearson R of 0.92 ± 0.01) and allow us to identify specific functional groups that appear to present challenges to the force field employed. One potentially valuable aspect of IDACs, as compared to solvation free energies, which have been frequently employed as force field tests, is that the same molecules serve both as solutes and solvents in different cases, allowing us to ensure that force fields are not overly tuned to one particular environment or solvent.
分子模拟始于一个基础能量模型或力场，并据此预测各种物理性质。然而，力场通常是基于相对有限的数据集开发的，而在广泛的化学空间中对各种性质的准确性是可取的；因此，此类准确性测试尤为重要。为此，我们计算了237个无限稀释活度系数（IDAC），并与美国国家标准与技术研究院（NIST）热化学数据库中的实验值进行比较。我们发现，计算得到的IDAC值与实验结果高度相关（皮尔逊相关系数R为0.92±0.01），并使我们能够识别出似乎对所采用的力场构成挑战的特定官能团。与经常用作力场测试的溶剂化自由能相比，IDAC的一个潜在有价值的方面是，相同的分子在不同情况下既作为溶质又作为溶剂，这使我们能够确保力场不会过度适应于一种特定环境或溶剂。
