苯的粗粒化力场:带电模型与不带电模型对比
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- 英文论文题名：Comparison of Two Coarse-Grained Models for Benzene:with and without Electrostatic Terms
- 论文作者：金钊 ; 曹风雷 ; 孙淮
- 英文论文作者：Zhao Jin ; Fenglei Cao ; Huai Sun ; School of Chemistry and Chemical Engineering ; Shanghai Jiao Tong University
- 年：2016
- 作者机构：上海交通大学化学化工学院;
- 论文关键词：粗粒化 ; 分子动力学 ; 苯 ; 分子力学力场
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十五分会：化学信息学与化学计量学
- 语种：中文
- 分类号：O625.11
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十五分会 ; 化学信息学与化学计量学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：139k
- 原文格式：D
- 会议级别：全国
摘要
本文针对在生命和材料科学中有广泛应用、具有典型的pi-pi相互作用的苯分子,构建并对比了两种适用于苯分子的粗粒化模型:不带电荷的三点模型和带电荷的四点模型。粗粒化模型为刚性结构,无分子内相互作用项;粗粒化粒子的质量通过转动惯量确定;电荷分布通过分子四极矩确定,电荷相互作用采用库仑势函数。由于粗粒化过程降低了模型的自由度,从而导致部分熵的丢失,因此对于分子间范德华相互作用项,我们采用与温度相关的显含熵贡献的FE-12-6函数~([1]),参数通过拟合气液相平衡共存曲线和蒸发焓实验值确定。计算结果证实两模型均可以准确的描述苯的临界性质、密度-温度变化曲线和表面张力-温度变化曲线,但三点模型无法预测晶体苯的结构,带电荷的四点模型可以预测晶体性质,得到的晶胞参数、密度、升华焓和压缩系数等性质和实验值吻合。由于涉及电荷计算,四点模型比三点模型计算量更大,效率较低。
In this work,we build two coarse-grained models for benzene:three-site uncharged model and four-site charged model.FE-12-6 potential is used to represent the non-bond interaction.The electrostatic interaction for four-site model is calculated with Coulomb potential function.The force field parameters are fitted by the vapor-liquid equilibrium data and heat of vaporization of benzene.Temperature-dependent and phase transformation terms should be added in order to present the entropy loss during the coarse-graining process.Both models can predict thermodynamic properties of liquid benzene such as critical properties,density and surface tension at a large temperature range.The four-site model performs well in the solid phase.It can be used to predict the structure of crystalline benzene approximately.
In this work,we build two coarse-grained models for benzene:three-site uncharged model and four-site charged model.FE-12-6 potential is used to represent the non-bond interaction.The electrostatic interaction for four-site model is calculated with Coulomb potential function.The force field parameters are fitted by the vapor-liquid equilibrium data and heat of vaporization of benzene.Temperature-dependent and phase transformation terms should be added in order to present the entropy loss during the coarse-graining process.Both models can predict thermodynamic properties of liquid benzene such as critical properties,density and surface tension at a large temperature range.The four-site model performs well in the solid phase.It can be used to predict the structure of crystalline benzene approximately.
引文
[1]Cao,F.;Sun,H.J.Chem.Theory Comput.2015,11:4760.