Abstract
The cooperative dynamical behaviour of disordered rotating molecules subject to steric hindrance is studied by extending Glauber's kinetic Ising model. A mean-field level approximation of the transition probabilities is proposed which describes multiorientational systems with steric hindrance. The coherent neutron scattering function S(Q, ω) of CBr4 in its plastic phase is obtained. The invoked correlations induce a strong Q dispersion of the HWHM Γ(Q) which explains the experimental behaviour