Values of ω^* calculated from the Zr isotopic cross sections (see Eq. (3)) as a function of the temperature. The ‘Tagliente original’ points are the values published in the Tagliente et al. papers listed in the main text, while the ‘Tagliente modified’ points are derived by scaling the theoretical kernels by 0.65. The error bars are derived propagating the relative error of 5% on all cross sections.