  We demonstrate using a simple model that in the frame of muffin-tin - like
potential non-physical peculiarities appear in molecular photoionization
cross-sections that are a consequence of jumps in the potential and its first
derivative at some radius. The magnitude of non-physical effects is of the same
order as the physical oscillations in the cross-section of a two-atomic
molecule. The role of the size of these jumps is illustrated by choosing three
values of it. The results obtained are connected to the studied previously
effect of non-analytical behavior as a function of r the potential V(r)acting
upon a particle on its photoionization cross-section. In reality, such
potential has to be analytic in magnitude and first derivative function in
distance. Introduction of non-analytic features in model potential leads to
non-physical features in the corresponding cross-section - oscillations,
additional maxima etc.
