ParamGULP: An efficient Python code for obtaining interatomic potential parameters for General Utility Lattice Program

General Utility Lattice Program (GULP) is an important software to the scientific community and available free for academic use. GULP allows studying several properties of solid materials since it has implemented an extensive list of interatomic potentials. However, an important step in the atomistic simulations is to determine the interatomic potential parameters and this step usually demands much time to be performed. In this work, we advance a user-friendly code written in the Python language called ParamGULP, which is designed to fit potential parameters with the help of the SciPy library. As far as we know, ParamGULP is the only Python code available for such a purpose and provides an alternative means of fitting to the algorithms built into GULP, being applied to any potential. In addition, the use and efficiency of our code were shown by applying it to obtain a set of interatomic potentials to reproduce the family of the RFeO_3 structures, where R stands for Dy, Er, Eu, Gd, Ho, Lu, Pr, Sm, Tb, Tm, and Yb. By considering some case studies, the benefits offered by ParamGULP for obtaining potential parameters could be noted. ParamGULP is designed to make the parameterization of interatomic potentials more efficient, further increasing and extending the use of GULP.