ℒ² Solution of the quantum mechanical reactive scattering problem. The threshold energy for D + H₂(v = 1) → HD + H

The first results of a new method for quantum mechanical calculations of chemical reaction probabilities are presented. The method involves the expansion of the amplitude density due to the difference between the true interaction potential and a distortion potential in a square integrable basis set and the solution of a large set of coupled equations for the basis function coefficients. We find a threshold energy for D + H₂(v=1) → HD + H, where v is the vibrational quantum number, in good agreement with previous semiclassical tunneling calculations.