论文标题
液态甲烷和乙烷的分布式电荷模型，以进行介电效应和溶剂化
Distributed Charge Models of Liquid Methane and Ethane for Dielectric Effects and Solvation
论文作者
论文摘要
液态碳氢化合物通常以固定的，对称，以原子为中心的电荷分布和Lennard-Jones相互作用电位进行建模，这些电位再现了大量液体的许多特性。尽管对于多种应用有用，但这种模型无法捕获对溶剂化，自组装和反应性重要的介电作用。烃的介电常数，例如甲烷和乙烷，从物理上是由波动液体环境引起的电子极化波动引起的。在这项工作中，我们提出了甲烷和乙烷的不可极化，固定荷尔兰模型，这些模型破坏了分子的电荷对称性以创建固定分子偶极子，从而重现了实验介电常数的波动。这些模型可以被视为平均场状近似值，可用于在液态甲烷和乙烷中的极性和带电分子的大规模分子模拟中包括介电作用。我们进一步证明，在这些固定偶极模型中，模型离子溶质和水分子的溶剂化在无偶极模型上可以改善。
Liquid hydrocarbons are often modeled with fixed, symmetric, atom-centered charge distributions and Lennard-Jones interaction potentials that reproduce many properties of the bulk liquid. While useful for a wide variety of applications, such models cannot capture dielectric effects important in solvation, self-assembly, and reactivity. The dielectric constants of hydrocarbons, such as methane and ethane, physically arise from electronic polarization fluctuations induced by the fluctuating liquid environment. In this work, we present non-polarizable, fixed-charge models of methane and ethane that break the charge symmetry of the molecule to create fixed molecular dipoles, the fluctuations of which reproduce the experimental dielectric constant. These models can be considered a mean-field-like approximation that can be used to include dielectric effects in large-scale molecular simulations of polar and charged molecules in liquid methane and ethane. We further demonstrate that solvation of model ionic solutes and a water molecule in these fixed-dipole models improve upon dipole-free models.
