A Python and Fortran code for automatically fitting permutationally invariant polynomials Authors Daniel R. Moberg and Ahren W. Jasper Argonne National Laboratory, 2021 Web: github.com/Auto-Mech/PIPPy Email: [email protected] References: (1) D. R. Moberg and A. W. Jasper, PIPPy, Argonne National Laboratory, 2021. (2) D. R. Moberg and A. W. Jasper, Permutationally invariant polynomial expansions with unrestricted complexity, J. Chem. Thoery Comput., submitted (2021)