Journal of Chemical Physics, Vol.110, No.15, 7354-7358, 1999
The interaction of H-2 with water ice by neutron scattering: Rotation and translation
The inelastic neutron scattering from H-2 in D2O ice at energy transfers that correspond to rotation-translation are presented. Both the first energy gain and the energy loss peaks are observed. The position of the peaks shows that the H-2 molecules execute nearly free rotation. The translational (recoil) contribution to the band positions as well as their widths can be fit by free translation with the molecule having an effective mass of about 1.7 M-0 where M-0 is the mass of H-2. The experimental results are compared to the available computer simulations.