Understanding the Dipole Moment of Liquid Water from a Self-Attractive Hartree Decomposition
Understanding the Dipole Moment of Liquid Water from a Self-Attractive Hartree Decomposition
复制标题
从自吸引哈特里分解了解液态水的偶极矩
DOI：
10.1021/acs.jpclett.0c03300
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Van Voorhis, Troy
中科院分区：
文献类型：
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作者：
Zhu, Tianyu;Van Voorhis, Troy
单个水分子在液态水中的偶极矩是理解水的介电性质的一个重要概念。在这项工作中，我们通过密度泛函理论计算的总电子密度的自吸引Hartree(SAH)分解，对从从头算分子动力学模拟的水团簇，研究了液态水的偶极矩。通过调整一个控制密度局域化程度的参数，我们揭示了两幅与整体介电性质一致的水偶极子的截然不同的图像：一幅是具有较小且较小极化的单体偶极子的局域图，另一幅是具有较大且较可极化的单体偶极子的非局域图。我们进一步发现，在局域图像中，集体偶极子-偶极相关性更强，并且是将单个偶极子与整体介电性质联系起来的关键。基于这些发现，我们建议在研究液态水的偶极矩时，同时考虑个人和集体的偶极行为，并为发展水模型提出新的设计策略。
The dipole moment of a single water molecule in liquid water has been a critical concept for understanding water’s dielectric properties. In this work, we investigate the dipole moment of liquid water through a self-attractive Hartree (SAH) decomposition of total electron density computed by density functional theory, on water clusters sampled from ab initio molecular dynamics simulation of bulk water. By adjusting one parameter that controls the degree of density localization, we reveal two distinct pictures of water dipoles that are consistent with bulk dielectric properties: a localized picture with smaller and less polarizable monomer dipoles and a delocalized picture with larger and more polarizable monomer dipoles. We further uncover that the collective dipole–dipole correlation is stronger in the localized picture and is key to connecting individual dipoles with bulk dielectric properties. On the basis of these findings, we suggest considering both individual and collective dipole behaviors when studying the dipole moment of liquid water and propose new design strategies for developing water models.