Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands.
J Chem Phys. 2012 Aug 14;137(6):064115. doi: 10.1063/1.4742154.
We develop an approximate field theory for particles interacting with a generalized Yukawa potential. This theory improves and extends a previous splitting field theory, originally developed for counterions around a fixed charge distribution. The resulting theory bridges between the second virial approximation, which is accurate at low particle densities, and the mean-field approximation, accurate at high densities. We apply this theory to charged, screened ions in bulk solution, modeled to interact with a Yukawa potential; the theory is able to accurately reproduce the thermodynamic properties of the system over a broad range of conditions. The theory is also applied to "dressed counterions," interacting with a screened electrostatic potential, contained between charged plates. It is found to work well from the weak coupling to the strong coupling limits. The theory is able to reproduce the counterion profiles and force curves for closed and open systems obtained from Monte Carlo simulations.
我们为与广义的雅可比（Yukawa）势相互作用的粒子发展了一个近似场论。这个理论改进并扩展了之前的分裂场理论，最初是为固定电荷分布周围的抗衡离子开发的。该理论在第二维里近似（在低粒子密度下准确）和平均场近似（在高密度下准确）之间架起了桥梁。我们将该理论应用于带有雅可比势相互作用的大块溶液中的带电、屏蔽离子，该理论能够在广泛的条件下准确再现系统的热力学性质。该理论也适用于带有屏蔽静电势的“修饰抗衡离子”，这些离子被包含在带电荷的板之间。从弱耦合到强耦合极限，发现它的效果都很好。该理论能够再现从蒙特卡罗模拟中获得的封闭和开放系统的抗衡离子分布和力曲线。
