论文标题
界面上水溶液的分子建模：远距离色散力和离子电荷重新缩放的效果
Molecular modeling of aqueous electrolytes at interfaces: effects of long-range dispersion forces and of ionic charge rescaling
论文作者
论文摘要
水解物的分子动力学模拟通常依赖于经验力场，结合了分散相互作用 - 由截短的Lennard -Jones（LJ）电位和静电相互作用描述 - 由用远程求解器计算出的库仑电位。最近，使用重新固定的离子电荷（电子连续校正，ECC）的力场可能与LJ参数重新缩放（电子连续校正校正，ECCR）相互补充，在散装中显示出令人鼓舞的结果，但其在接口处的性能较少。在这里，我们首先探索LJ电势截断对氯化钠水溶液表面张力的影响。我们显示了与较大的截止的截短LJ相互作用的数值预测与使用远距离求解器计算的未截断的LJ相互作用的数值预测之间的差异，这可能会偏向力场预测与实验的比较。 Using a long-range solver for LJ interactions, we then show that an ionic charge rescaling factor chosen to correct long-range electrostatic interactions in bulk also describes accurately image charge repulsion at the liquid-vapor interface, and that the rescaling of LJ parameters in ECCR models - aimed at capturing local ion-ion and ion-water interactions in bulk - also describes well the formation of an ionic double layer at the液体蒸气界面。总体而言，这些结果表明，在接口处水溶液的分子建模将受益于使用远程求解器用于分散力，以及使用ECCR模型，其中应选择电荷恢复因子以纠正远距离静电相互作用。
Molecular dynamics simulations of aqueous electrolytes generally rely on empirical force fields, combining dispersion interactions - described by a truncated Lennard-Jones (LJ) potential - and electrostatic interactions - described by a Coulomb potential computed with a long-range solver. Recently, force fields using rescaled ionic charges (electronic continuum correction, ECC), possibly complemented with rescaling of LJ parameters (electronic continuum correction rescaled, ECCR), have shown promising results in bulk, but their performance at interfaces has been less explored. Here we started by exploring the impact of the LJ potential truncation on the surface tension of a sodium chloride aqueous solution. We show a discrepancy between the numerical predictions for truncated LJ interactions with a large cutoff and for untruncated LJ interactions computed with a long-range solver, which can bias comparison of force field predictions with experiments. Using a long-range solver for LJ interactions, we then show that an ionic charge rescaling factor chosen to correct long-range electrostatic interactions in bulk also describes accurately image charge repulsion at the liquid-vapor interface, and that the rescaling of LJ parameters in ECCR models - aimed at capturing local ion-ion and ion-water interactions in bulk - also describes well the formation of an ionic double layer at the liquid-vapor interface. Overall, these results suggest that the molecular modeling of aqueous electrolytes at interfaces would benefit from using long-range solvers for dispersion forces, and from using ECCR models, where the charge rescaling factor should be chosen to correct long-range electrostatic interactions.
