This code adjusts interatomic potentials from a reference database of atomic structures and their corresponding DFT energies. For the calculation of energies from atomic positions, it uses the GULP program via an interface. The adjustment of the potentials is done by means of a genetic algorithm. The code has been tested for the calculation of interatomic potentials of perovskites PbCs(Br,I,Cl)3. The calculation of the reference database of energies and geometries was calculated using the VASP code. The article can be found published in: SRG Balestra et al., J. Mater. Chem. A, 2020,8, 11824-11836, DOI: 10.1039/D0TA03200J and the preprint in arxiv: 2003.09360.