水溶液中多原子离子旋转平移动力学的统一图象
A unified picture of roto-translational dynamics in aqueous polyatomic ions
摘要：
模式耦合理论提供了多原子离子转动和平移动力学的统一描述。这些分子离子不同于通常的离子扩散模型，例如K+、Cl-等，并且也不同于通常在介电连续模型中建模为点偶极子的偶极分子的旋转动力学。这两种方法对于多原子离子都是站不住脚的。在这里，旋转和平移动力学是如此强烈地耦合在一起，以至于人们通过将它们一起处理来获得更连贯的描述。我们对一系列著名的多原子离子，即硫酸根、硝酸根和乙酸根离子进行了理论和计算研究。三种离子都表现出不同的旋转扩散系数，硝酸根离子的旋转扩散系数明显大于其他两种离子。它们都违反了流体力学的大小依赖定律。对离子周围局部结构的研究为这些差异的起源提供了有价值的见解。我们进行了详细的研究，这些离子的旋转扩散广泛的计算机模拟和使用的理论方法的介电摩擦开发的Fatuzzo梅森（FM）和Nee-Zwanzig（新西兰），随后由Alavi和Waldeck推广。我们开发了一个自洽模式耦合理论（SC-MCT）的形式主义，有助于阐明这些离子的平移和旋转运动之间的耦合作用。事实上，这两个运动自洽地决定了彼此的值。基于RISM的MCT给出了力矩-力矩和力-力-时间关联函数之间的有趣关系，其比例常数由多原子分子的几何形状和电荷分布决定，指出了偶极液体中离子的平移摩擦和旋转摩擦计算理论之间的若干相似性.
英文摘要：
Mode-coupling theory provides a unified description of the rotational and translational dynamics of polyatomic ions. These molecular ions are distinct from usual models of ion diffusion, such as K+ , Cl- etc., and also different from rotational dynamics of dipolar molecules often modeled in dielectric continuum models as point dipoles. Both these approaches are untenable for polyatomic ions. Here rotational and translational dynamics are so strongly coupled that one obtains a more coherent description by treating them together. We carry out theoretical and computational studies of a series of well-known polyatomic ions, namely sulfate, nitrate and acetate ions. All the three ions exhibit different rotational diffusivity, with that of nitrate ion being considerably larger than the other two. They all defy the hydrodynamic laws of size dependence. Study of the local structure around the ions provides valuable insight into the origin of these differences. We carry out a detailed study of the rotational diffusion of these ions by extensive computer simulation and using the theoretical approaches of the dielectric friction developed by Fatuzzo-Mason (FM) and Nee-Zwanzig (NZ), and subsequently generalized by Alavi and Waldeck. We develop a self-consistent mode-coupling theory (SC-MCT) formalism that helps elucidating the role of coupling between translational and rotational motion of these ions. In fact, these two motions self-consistently determine the value of each other. The RISM-based MCT suggests an interesting relation between the torque-torque and the force-force time correlation function with the proportionality constant being determined by the geometry and the charge distribution of the polyatomic molecule.We point out several parallelism between the theories of translational and rotation friction calculations of ions in dipolar liquids.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
