I am trying to fit 5 phases of a binary oxide (hafnium) with Morse-Lenard potential. I already have the potential parameters from literature, but I am trying to fit spring, and charge of core and accordingly shell. Phases are: ferroelectric, cubic, tetragonal, monoclinic, and ortho-pnma.
I have been doing many trials, but all generate errors or strange results after the fit. O spring after the fit becomes very large in the order of 5000000. I really need help if any can help and check the input file with me if possible.