Atomic charges of the water molecule and the water dimer
Atomic charges of the water molecule and the water dimer
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DOI：
10.1021/jp980574e
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发表时间：
1998-09-24
影响因子：
2.9
通讯作者：
Helgaker, T
中科院分区：
文献类型：
--
作者：
Åstrand, PO;Ruud, K;Helgaker, T
水分子和水二聚体中的原子电荷用Mulliken电荷和基于极性张量的原子电荷这两种分配总电荷分布的方法来计算。已经进行了大规模的计算，其中基集已系统地向基集极限增加。Mulliken电荷对基的选择高度敏感，没有收敛现象。相反，从原子极张量的轨迹得到的原子电荷表现出快速的基集收敛。我们还研究了电子相关对水分子原子电荷的影响。最后，计算了水二聚体的极化和电荷转移效应对原子电荷的影响。讨论了在水溶液分子动力学模拟中使用的水势中这些术语的重要性。
Atomic charges in the water molecule and the water dimer have been calculated by two different schemes for partitioning the total charge distribution: Mulliken charges and atomic polar tenser-based charges. Large-scale calculations have been carried out where the basis set has been increased systematically toward the basis-set Limit. The Mulliken charges are highly sensitive to the choice of basis, and no convergence is observed. In contrast, atomic charges obtained from the trace of the atomic polar tensor exhibit rapid basis-set convergence. We have also investigated the effects of electron correlation on the atomic charges of the water molecule. Finally, the polarization and charge-transfer effects on the atomic charges have been calculated for the water dimer. The importance of such terms in a water potential used in molecular dynamics simulations of aqueous solutions is discussed.