Viscoelastic behavior of water in the terahertz-frequency range: an inelastic x-ray scattering study.


High-resolution, inelastic x-ray scattering measurements of the dynamic structure factor S(q,omega) of liquid water in the THz frequency range have been performed as a function of wave vector q (1-7 nm(-1)) and temperature T (273-473 K), using pressure (0-1.5 kbar) to keep the density at rho approximately 1 g/cm(3). We show that, for q<or=2 nm(-1), the S(q… (More)