O using Inelastic Neutron Scattering*

We report the real-space correlated molecular dynamics in heavy water (D₂O). Dynamic structure factor, S(Q, E), obtained from high-resolution inelastic neutron scattering data over large Q (momentum transfer) and E (energy transfer) is double-Fourier transformed to obtain the Van Hove function, which is a time-dependent pair-correlation function. A two-step relaxation is observed in the intermolecular dynamics of D₂O. Its relaxation time and amplitude depends on the temperature. By comparing the results with classical MD simulations of D₂O and inelastic x-ray scattering measurements of H₂O^[1][2], correlated dynamics of water molecules in ps time-scale is discussed.

References
1. T. Iwashita et al, Science Advances 3, e1603079 (2017).
2. Y. Shinohara et al, Phys. Rev. E 98, 022604 (2018).