Non-physical consequences of the Muffin-tin-type intra-molecular potential

TL;DR

This paper shows that using muffin-tin-like potentials in molecular photoionization models introduces non-physical artifacts in the cross-sections due to potential jumps, which are comparable in size to real physical oscillations.

Contribution

It demonstrates that non-analytic features in model potentials cause non-physical effects in photoionization cross-sections, highlighting the importance of using smooth, analytic potentials.

Findings

Non-physical oscillations appear in cross-sections due to potential jumps.

The magnitude of artifacts is comparable to physical oscillations.

Non-analytic potential features lead to artificial maxima and oscillations.

Abstract

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.