Low-Terahertz Spectroscopy of Liquid Water

摘要

In this work we present the results on combined experimental and computational study of sub-THz spectra of liquid water. The important new result is the detection of hydrogen bonds in liquid water. The experimental study was performed by employing Fourier Transform terahertz (THz) spectroscopy with spectral resolution of 0.25 cm~(-1). Resonance features in transmission spectra of water layers between thin film substrates are demonstrated in the sub-THz range. The theoretical approach for computer simulation of THz absorption spectra from liquid water is also discussed. The molecular dynamical (MD) simulations of water were performed using Amber 8 and the TIP3P, SPCE (Extended Single Point Charge) and TIP4P water models. Several examples of modeling results are presented. The experimental spectra are compared with the theoretical predictions. The SPCE model better correlates with experimental spectra compare to two other models.