We have utilized an approach that integrates molecular dynamics (MD) simulations with particle swarm optimization (PSO) to accelerate the development of coarse-grained (CG) models of hydrocarbons. Specifically, we have developed new transferable CG beads, which can be used to model the hydrocarbons (C5 to C17) and reproduce their experimental properties with good accuracy. First, the PSO method was used to develop the CG beads of the decane model represented with a 2:1 (2-2-2-2-2) mapping scheme. This was followed by the development of the nonane model described with hybrid 2-2-3-2 and 3:1 (3-3-3) mapping schemes. The force-field parameters for these three CG models were optimized to reproduce four experimentally observed properties including density, enthalpy of vaporization, surface tension, and self-diffusion coefficient at 300 K. The CG MD simulations conducted with these new CG models of decane and nonane, at different timesteps, for various system sizes, and at a range of different temperatures, were able to predict their density, enthalpy of vaporization, surface tension, self-diffusion coefficient, expansibility, and isothermal compressibility with good accuracy. Moreover, a comparison of structural features obtained from the CG MD simulations and the CG beads of mapped all-atom trajectories of decane and nonane showed very good agreement. To test the chemical transferability of these models, we have constructed the models for hydrocarbons ranging from pentane to heptadecane, by using different combinations of the CG beads of decane and nonane. The properties of pentane to heptadecane predicted by these new CG models showed excellent agreement with the experimental data.

中文翻译：

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新型可转移粗粒碳氢化合物模型的开发

我们采用了一种将分子动力学（MD）模拟与粒子群优化（PSO）相集成的方法，以加快碳氢化合物粗粒（CG）模型的开发。具体来说，我们开发了新的可转移CG珠，可用于对碳氢化合物（C5至C17）进行建模，并以良好的精度重现其实验性质。首先，使用PSO方法开发以2：1（2-2-2-2-2）映射方案表示的癸烷模型的CG珠。随后开发了使用混合2-2-3-2和3：1（3-3-3）映射方案描述的壬烷模型。优化了这三个CG模型的力场参数，以重现四个实验观察到的特性，包括密度，汽化焓，表面张力和300 K下的自扩散系数。使用这些新的癸烷和壬烷CG模型在不同的时间步长，不同的系统尺寸和不同的温度范围内进行CG MD模拟，可以预测它们的密度，汽化焓，表面张力，自扩散系数，可膨胀性和等温压缩性具有良好的精度。此外，从CG MD模拟获得的结构特征与癸烷和壬烷的映射全原子轨迹的CG珠的比较显示出很好的一致性。为了测试这些模型的化学转移性，我们通过使用癸烷和壬烷的CG珠的不同组合，构建了从戊烷到庚烷的碳氢化合物模型。