Global Diabatic Potential Energy Surfaces of the PH₂⁺ System and Dynamics Studies of the P⁺(³P) + D₂ Reaction

Global diabatic potential energy surfaces (PESs) of the PH₂⁺ associated with 1³A″ and 2³A″ states were constructed by using a neural network method combined with a symmetry-adapted function. In the construction of PESs, high-level ab initio points were calculated by the multireference configuration interaction method in conjunction with the aug-cc-pVQZ basis set for H and the aug-cc-pwCVQZ basis set for P. The topographical features of the diabatic PESs were discussed and compared with the ab initio results, confirming that the diabatic PESs were successfully constructed. To further validate the reliability of the diabatic PESs, adiabatic and nonadiabatic dynamics calculations of the P⁺(³P) + D₂ reaction were performed using a time-dependent wave packet method. The integral cross sections were reported and compared with experimental data. The results indicate that the nonadiabatic values are, in general, in good agreement with experimental data, while the adiabatic dynamics results tend to overestimate the actual values.