Leontyev Igor V, Stuchebrukhov Alexei A
Department of Chemistry, University of California Davis, One Shields Avenue, Davis, California 95616, USA.
J Chem Phys. 2014 Jul 7;141(1):014103. doi: 10.1063/1.4884276.
Earlier, using phenomenological approach, we showed that in some cases polarizable models of condensed phase systems can be reduced to nonpolarizable equivalent models with scaled charges. Examples of such systems include ionic liquids, TIPnP-type models of water, protein force fields, and others, where interactions and dynamics of inherently polarizable species can be accurately described by nonpolarizable models. To describe electrostatic interactions, the effective charges of simple ionic liquids are obtained by scaling the actual charges of ions by a factor of 1/√(ε(el)), which is due to electronic polarization screening effect; the scaling factor of neutral species is more complicated. Here, using several theoretical models, we examine how exactly the scaling factors appear in theory, and how, and under what conditions, polarizable Hamiltonians are reduced to nonpolarizable ones. These models allow one to trace the origin of the scaling factors, determine their values, and obtain important insights on the nature of polarizable interactions in condensed matter systems.
此前，我们采用现象学方法表明，在某些情况下，凝聚相系统的可极化模型可以简化为具有缩放电荷的非可极化等效模型。此类系统的例子包括离子液体、水的TIPnP型模型、蛋白质力场等，其中固有可极化物种的相互作用和动力学可以通过非可极化模型准确描述。为了描述静电相互作用，简单离子液体的有效电荷是通过将离子的实际电荷按1/√(ε(el))的因子进行缩放得到的，这是由于电子极化屏蔽效应；中性物种的缩放因子则更为复杂。在这里，我们使用几种理论模型，研究缩放因子在理论中究竟是如何出现的，以及可极化哈密顿量如何以及在何种条件下简化为非可极化哈密顿量。这些模型使我们能够追溯缩放因子的起源，确定其值，并获得关于凝聚态物质系统中可极化相互作用本质的重要见解。
