I want to conduct molecular static simulation of ferrite-chromium-helium. I want to calculate adhesion of helium on this alloy and I need to choose potential. I found only repulsive potential of He-Cr and I do not know if this is the only option.
No. The Helium - Chromium ground state pair potential is not only repulsive. There is a small Van-der-waals attraction. I have calculated it on my own with a coupled cluster CCD(T) calculation and large cc basis sets (and some pepper). The Minimum is about 4.6 cm-1 at a distance of 5.2 Angstrom.
For more literature I encourage you to take a look in papers from the helium droplet community - e.g. http://www.ncbi.nlm.nih.gov/pubmed/24906160