A three-point coarse-grained model of five-water cluster with permanent dipoles and quadrupoles
A three-point coarse-grained model of five-water cluster with permanent dipoles and quadrupoles
复制标题
永久偶极子和四极子五水团簇的三点粗粒度模型
DOI：
10.1039/d0cp04782a
复制
发表时间：
2020-12-07
影响因子：
3.3
通讯作者：
Zhang, John ZengHui
中科院分区：
文献类型：
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作者：
Li, Min;Lu, WenCai;Zhang, John ZengHui
随着对生物大分子的粗粒度(CG)研究的增加，开发可靠的CG溶剂模型变得尤为重要。在这项工作中，我们将五个水分子简化为一个具有永久偶极矩和四极矩的三点CG模型。在CG力场中，利用修正的Morse势，设计一个理想的三水团簇，得到CG级的永久多极子。新的CG模型是在阿米巴可极化力场上进行参数化的。为了验证新的CG模型，对液态水的各种重要性质进行了检验。结果表明，新的CG模型能够正确地再现某些重要的实验性质，如密度、等温压缩系数和相对静态介电常数，甚至优于现有的AA模型。此外，CPU测试表明，与流行的AA力场相比，CG模型可以将分子动力学模拟的速度提高19倍。与其他CG模型中广泛使用的定点电荷模型相比，基于永久多极的CG模型描述了更多的刚性静电引力。这项研究还表明，在CG模拟中，永久多极矩对静电计算的贡献很大。
As coarse-grained (CG) studies of large biomolecules increase, developments of reliable CG solvent models become particularly important. In this work, we reduce five water molecules into a three-point CG model with permanent dipole and quadrupole moments. In the CG force field, the modified Morse potential is utilized and an ideal three-water cluster is designed to derive CG-level permanent multipoles. The new CG model is parametrized on the AMOEBA polarizable force field. Various important properties of liquid water are examined to validate the new CG model. Results show that the new CG model can correctly reproduce certain important experimental properties such as density, isothermal compressibility and relative static dielectric permittivity, even better than the existing AA models. Additionally, the CPU tests reveal that the CG model can accelerate molecular dynamics simulations by a factor of 19 compared to the popular AA force field. Compared with the fix-point-charge model widely used in other CG models, the permanent-multipole-based CG model describes more rigid electrostatic attractions. This study also illustrates that the permanent multipole moments contribute a lot to the electrostatic calculations in CG simulation.