Abstract
The asymptotic expansion of the incoherent-scattering function in inverse powers of the magnitude of the momentum transfer κ, which was given in a previous article for simple classical liquids, is generalized within the Gaussian approximation to include quantum effects. Inverse-κ expansions are also obtained for the full width at half-maximum, the mean frequency, and the frequency of the maximum of the scattering function. The results are applied in the interpretation of recent neutron-inelastic-scattering data for liquid neon, liquid rubidium, and hydrogen gas.