DYNAMICAL FLUCTUATING CHARGE FORCE-FIELDS - APPLICATION TO LIQUID WATER
DYNAMICAL FLUCTUATING CHARGE FORCE-FIELDS - APPLICATION TO LIQUID WATER
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DOI：
10.1063/1.468398
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发表时间：
1994-10-01
影响因子：
4.4
通讯作者：
BERNE, BJ
中科院分区：
文献类型：
--
作者：
RICK, SW;STUART, SJ;BERNE, BJ
一种新的分子动力学模型，其中原子位置上的点电荷允许响应于开发的环境而波动，并应用于水。将电荷视为变量的想法是基于电负性均衡的概念，根据该概念：（a）原子位置的电负性取决于原子的类型和电荷，并且受到其从其邻居经历的静电势的扰动，以及（B）电荷以电负性均衡的方式在原子位置之间转移。使用扩展的拉格朗日方法将电荷作为动力学变量处理，其中电荷被赋予虚拟质量、速度和动能，然后根据牛顿力学沿着原子自由度传播。利用两种常见的固定电荷水势的几何形状：简单点电荷（SPC）和四点可转移分子间势（TIP 4P），建立了具有波动电荷的水模型。这两个波动电荷模型给出了准确的预测气相和液体状态的属性，包括径向分布函数，介电常数，和扩散常数。的;方法不引入任何新的分子间相互作用超出那些已经存在于固定电荷模型和增加计算机时间只有1.1的一个因素，使这种方法易于处理的大型系统。
A new molecular dynamics model in which the point charges on atomic sites are allowed to fluctuate in response to the environments developed and applied to water. The idea for treating charges as variables Is based on the concept of electronegativity equalization according to which: (a) the electronegativity of an atomic site is dependent on the atom's type and charge and is perturbed by the electrostatic potential it experiences from its neighbors and (b) charge is transferred between atomic sites in such a way that electronegativities are equalized. The charges are treated as dynamical variables using an extended Lagrangian method in which the charges are given a fictitious mass, velocities, and kinetic energy and then propagated according to Newtonian mechanics along with the atomic degrees of freedom. Models for water with fluctuating charges are developed using the geometries of two common fixed-charge water potentials: die Simple point charge (SPC) and the four-point transferable intermolecular potential (TIP4P). Both fluctuating charge models give accurate predictions for gas-phase and liquid state properties, including radial distribution functions, the dielectric constant, and the diffusion constant. The;method does not introduce any new intermolecular interactions beyond those already present in the fixed charge models and increases the computer time by only a factor of 1.1, making this method tractable for large systems.