Abstract Classical molecular dynamics (MD) simulations were performed to study the association of KF and NaF ion pairs in water in a wide range of temperatures (423–1273 K) and densities (0.10–0.60 g/cm3). The association constants (KA) derived from the potentials of mean force (PMF) exhibit a rising tendency as temperature increases or density decreases. The association of NaF is similar to KF under most conditions but evidently larger at higher temperatures and lower densities. The radial distribution function (RDF) and coordination number (CN) reveal the characteristics of ion-water microstructures. There is significant water clustering near the K+/Na+ at high temperatures or low densities. The results indicate that fluoride ion acts as an important ligand complexing with K+/Na+ and promotes their migration and concentration in hydrothermal fluids.

中文翻译：

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热液中KF和NaF离子对的分子动力学模拟研究

摘要 进行经典分子动力学 (MD) 模拟以研究在广泛的温度 (423–1273 K) 和密度 (0.10–0.60 g/cm3) 下水中 KF 和 NaF 离子对的关联。来自平均力 (PMF) 势能的关联常数 (KA) 表现出随着温度升高或密度降低而上升的趋势。NaF 的结合在大多数条件下与 KF 相似，但在较高温度和较低密度下明显更大。径向分布函数（RDF）和配位数（CN）揭示了离子-水微结构的特征。在高温或低密度下，K+/Na+ 附近有明显的水聚集。