PES2MP: A Python Application for Automating Collisional Dynamics of Linear Rigid-Rotors

The program (with GUI Interface) can generate Psi4-based potential energy surface internally (with capabilities to create input files for Gaussian, Molpro, and Psi4 for external calculations) for atom-atom (1D), rigid rotor(RR)-atom (2D), and RR-RR (4D) collision. A TensorFlow (keras) based neural-networks model can be created to augment the surface with a high degree of accuracy (at both minima and high energy regions), OR (if angular augmentation is not necessary) radial terms for each angle(s) can be analytically fitted to get missing R values. Finally, the PES is fitted into Legendre (2D) and Bispherical Harmonics (4D) to get radial terms which can be used to study rotational transitions induced by the collider. The codes are useful while studying collisional 💥 dynamics of one or both species at cold ❄️ and ultracold ⛄ temperatures.