Key Laboratory of Chemical Biology and Molecular Engineering of the Education Ministry, Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, China.
J Chem Phys. 2010 Mar 28;132(12):124503. doi: 10.1063/1.3369624.
Potassium ion in water plays a very important role in chemistry and biology. In this paper, we investigated the hydration structure and coordination of K(+) solvation in water at 300 and 450 K using ab initio Car-Parrinello molecular dynamics. The K(+)-oxygen radial distribution function indicated that the perturbation of K(+) on the water structure is strong in the first hydration shells, while it is mild outside of this region in normal liquid. According to our natural geometric criterion for the coordinated oxygen atom, the average coordination number of K(+) is 6.24 and 6.53 at 300 and 450 K, respectively, which agrees with the experimental value (6.1). This geometric criterion can also be used to define strong, moderate and weak hydrogen bonds in liquid.
水中的钾离子在化学和生物学中起着非常重要的作用。在本文中，我们使用从头算 Car-Parrinello 分子动力学研究了 300 和 450 K 下 K(+)在水中的水合结构和配位情况。K(+)-氧的径向分布函数表明，K(+)在第一层水合壳中对水结构的扰动很强，而在正常液体的这个区域之外则很温和。根据我们对配位氧原子的自然几何标准，K(+)在 300 和 450 K 时的平均配位数分别为 6.24 和 6.53，与实验值(6.1)相符。该几何标准也可用于定义液体中的强、中和弱氢键。
