On the basis of the successful reproducibility of the band at ∼200 cm⁻¹ (6 THz) in the far-infrared (terahertz) spectrum of liquid water by spectral simulations, and the intermolecular charge flux as the primary mechanism giving rise to the intensity of this band, the dynamical behavior of the molecular partial charges in liquid water implied by the presence of this band is examined theoretically. The molecular partial charges are typically within the range of ±0.03 e, with frequent short-time (<0.1 ps) excursions out of this range, and are rapidly modulated with a time constant of ∼0.12 ps. The long-time behavior of the time correlation function in the 0.3–10 ps region is related to the topological nature of the related molecular motions. The implication of the results on the use of time-domain terahertz spectroscopy to detect the properties of molecular motions in various environments is discussed.

通过光谱模拟成功地再现了液态水的远红外（太赫兹）光谱中〜200 cm ^-1 （6 THz）的能带，并且分子间电荷通量是产生强度的主要机理在该谱带的理论上，研究了由该谱带的存在所暗示的液态水中分子部分电荷的动力学行为。分子部分电荷通常在±0.03 e的范围内的短时偏移（<0.1 ps）超出此范围，并以〜0.12 ps的时间常数进行快速调制。时间相关函数在0.3–10 ps区域内的长期行为与相关分子运动的拓扑性质有关。讨论了使用时域太赫兹光谱技术来检测各种环境中分子运动的性质的结果的含义。