Improved techniques for outgoing wave variational principle calculations of converged state-to-state transition probabilities for chemical reactions

We present improved techniques and well-optimized basis sets for application of the outgoing wave variational principle to calculate converged quantum mechanical reaction probabilities, and we illustrate them with calculations for the reactions D + H₂ → HD + H with total angular momentum J = 3 and F + H₂ → HF + H with J = 0 and 3. The optimization involves the choice of distortion potential, the grid for calculating half-integrated Green's functions, the placement, width, and number of primitive distributed Gaussians, and the computationally most efficient partition between dynamically adapted and primitive basis functions. We present benchmark calculations with 224-1064 channels.