A model-independent procedure is proposed which allows us to obtain the asymptotic scaling function at infinite momentum transfer and a comprehensive assessment of deviations of deep inelastic-neutron-scattering data from a perfect scaling behavior, which are due to the finite values of energy and momentum transfers to the target atom. The procedure is applied to simulated and experimental data on polycrystalline Zr${\mathrm{H}}_2$ at $T=20\mathrm{} \mathrm{and} 290$ K. We observe that the impulse approximation, valid for infinite energy and momentum transfers, is not yet completely reached at the finite momentum transfer values $q$ of neutron experiments even at $q\simeq 60$ ${\mathrm{\AA }}^{-1\mathrm{}}$. It is argued that, beyond the specific case of Zr${\mathrm{H}}_2$, this procedure can be used for the description of deep inelastic-neutron scattering from other molecular and atomic systems.

• Received 11 March 1996

DOI:https://doi.org/10.1103/PhysRevB.54.6255