ROTATIONAL MOLECULAR-DYNAMICS IN THE R-I PHASE OF N-NONADECANE

Reorientational dynamics of n-nonadecane molecules in the R-I phase ha ve been investigated by means of molecular dynamics computer simulatio ns (MD) and incoherent quasielastic neutron scattering (IQNS) techniqu es. Models based on jump process and rotational diffusion are compared with the calculated intermediate scattering Functions and with the ex perimental spectra. A four-site jump model must be ruled out while a m odel based on a fourfold potential with two different barriers could b e used to interpret the data successfully.