However, its application in nonadiabatic dynamics has been limited by the non-smoothness of the potential energy surfaces when two states are close in energy and strongly mixed, like in the proximity of CoIns and avoided crossing between two surfaces. This has been fixed by the introduction of XMS-CASPT2 which solves this problem, arising due to the overestimation of off-diagonal elements of the Hamiltonian that leads the mixing coefficients of the wavefunctions of the different states to be non-smooth, by defining a Hamiltonian that considers the entire Fock operator. Very recently, XDW-CASPT2 has been introduced, aiming to combine the accuracy of the MS-CASPT2 energies and the smoothness of XMS-CASPT2 potentials. XDW-CASPT2 interpolates between the two methods according to how separated or close the states are, introducing a dynamic weight in the construction of the Fock operators, following either a state-specific or state-average approach. However, the original implementation XDW-CASPT2 would not be suitable for nonadiabatic dynamics when the electronic energies are calculated on-the-fly, since imposing a symmetry is required to avoid the mixing of states of different symmetry. However, in dynamics, no symmetry is imposed. In a more recent formulation, 60 new ways to define such exponents for the weights are been defined, which also include the symmetry of the states and we thought it would be worth it to test this in nonadiabatic dynamics. In our interface, we left the way and the factors necessary to compute the weights as default and recommended in OpenMolcas to avoid symmetry-related problems, but the user can easily modify the setup. Further slight modifications led to the development of RMS-CASPT2, which improves the description of XDW-CASPT2 as it does not mix states that belong to different irreducible representations, and offers a parameter-free derivation, removing the need to define an empirical parameter to control how to weight between state-average and specific. For all the flavors, in our implementation imaginary and IPEA shifts can be defined in the submission of the dynamics, although values of 0.2 and 0.0 respectively are assigned by default. As our interface is designed to exploit all the functionality of OpenMolcas, restricted active space, RASSCF, and RASPT2 calculations are also theoretically possible, to include a bigger active space. However, due to the large number of single-point calculations needed to propagate long enough dynamics and compute all the quantities required by PySpawn, an accurate cost/benefit analysis is recommended before running such simulations, so this is the reason why by default CASSCF/CASPT2 calculations is setup. The interface is included in PySpwawn, which is available on Git at .