Quantum calculations of H2–H2 collisions: From ultracold to thermal energies

We present quantum dynamics of collisions between two para-H(2) molecules from low (10(-3) K) to high collision energies (1 eV). The calculations are carried out using a quantum scattering code that solves the time-independent Schrodinger equation in its full dimensionality without any decoupling approximations. The six-dimensional potential energy surface for the H(4) system developed by Boothroyd et al. [J. Chem. Phys. 116, 666 (2002)] is used in the calculations. Elastic, inelastic, and state-to-state cross sections as well as rate coefficients from T=1 K to 400 K obtained from our calculations are compared with available experimental and theoretical results. Overall, good agreement is obtained with previous studies.