Spectroscopic analysis of transition state energy levels: Bending-rotational spectrum and lifetime analysis of H₃ quasibound states

We report converged quantum mechanical calculations of scattering matrices and transition probabilities for the reaction of H with H₂ with total angular momentum 0, 1, and 4 as functions of total energy in the range 0.85-1.15 eV on an accurate potential energy surface. These calculations show energy dependences that may be attributed to dynamical resonances with vibrational quantum numbers (10⁰0) and (11¹0). The resonance structure is illustrated with Argand diagrams, and we present state-to-state reactive collision delay times and lifetimes. For J = 0, 1, and 4, we found the lowest-energy H₃ resonance at total energies of 0.983, 0.985, and 1.01 eV, respectively, with lifetimes of about 16-17 fs. For J = 1 and 4 there is a higher-energy resonance at 1.10-1.11 eV; for J = 1 the lifetime is about 4 fs and for J = 4 it is about 1 fs.