In this work we have studied weak processes such 𝛽−decay and neutrino capture that are very important for the r-process. This process takes place far from the 𝛽−stability line, that means in a region where data are very scarce experimentally. In order to study the nucleosynthesis of elements heavier than iron it is necessary to know the cross sections of neutrino-nucleus processes for these nuclei. We have fitted results obtained by Gross Theory of Beta Decay (GTBD) applied to neutrinonucleus cross sections. We used a four degree polynomial dependence of the cross section with the incident neutrino energy in fitting Gross Theory theoretical results. This dependence allows us to systematically calculate the neutrino-nucleus cross sections for a large group of nuclei, such as those needed in the r-process (more than 4000 nuclei). Our fitting and interpolation procedures are shown to be in a good agreement and the GTBD cross sections are successfully reproduced.