Global Diabatic Potential Energy Surfaces for the Two Lowest States of Li₃

We constructed a new set of diabatic potential energy surfaces (PESs) for the two lowest states involved in Li+Li₂ reaction by using the fundamental-invariant neural network method. The Li₃ system exhibits a conical intersection (CI) at the geometric D_3h symmetries with the energy of the CI point significantly lower than the ground-state energy of the diatomic molecule. The diabaitc PESs accurately reproduce ab\; initio adiabatic energies, derivative coupling, and energy gradient information, thereby providing a high-fidelity description of the CI between the two lowest electronic states. Quantum dynamical calculations have revealed significant non-adiabatic effects in the Li+Li₂ reaction.