Fadgen Andrew M, Pizzi Nicholas A, Wigent Rodney J, Moore Preston B
Saint Joseph's University, 600 S. 43rd Street, Philadelphia, Pennsylvania 19104, United States.
J Phys Chem B. 2025 Jan 9;129(1):417-422. doi: 10.1021/acs.jpcb.4c07206. Epub 2024 Dec 20.
Molecular dynamics simulations are a powerful tool for probing and understanding the theoretical aspects of chemical systems and solutions. Our research introduces a novel method for determining the excess chemical potential of non-ideal solutions by leveraging the equivalence between the chemical potential of the vapor phase and liquid phase. Traditional approaches have relied on bulk simulations and the integration of pair distribution functions (()), which are computationally intensive to obtain accurate results. In contrast, our method utilizes a liquid-gas system, where determining the vapor pressure allows for a quick and accurate calculation of the excess chemical potential relative to a reference system, e.g., pure solvent. This approach significantly reduces computational effort while maintaining high accuracy and precision. We demonstrate the effectiveness of this method using a simplified Lennard-Jones model, although the method is broadly applicable to a wide range of systems, including those with complex interactions, varying concentrations, and different temperatures. The reduced computational demands and versatility of our approach make it a valuable tool for studying non-ideal solutions, including ionic solutions in molecular simulations.
分子动力学模拟是探究和理解化学系统及溶液理论方面的有力工具。我们的研究引入了一种新方法，通过利用气相和液相化学势之间的等效性来确定非理想溶液的过量化学势。传统方法依赖于整体模拟和对分布函数（()）的积分，要获得准确结果计算量很大。相比之下，我们的方法利用液 - 气系统，通过确定蒸气压，可以相对于参考系统（例如纯溶剂）快速准确地计算过量化学势。这种方法在保持高精度和高精确度的同时，显著减少了计算量。我们使用简化的 Lennard-Jones 模型证明了该方法的有效性，尽管该方法广泛适用于各种系统，包括具有复杂相互作用、不同浓度和不同温度的系统。我们方法降低的计算需求和通用性使其成为研究非理想溶液（包括分子模拟中的离子溶液）的宝贵工具。
