Probabilities for the F+H2→HF+H reaction by the hyperquantization algorithm:: alternative sequential diagonalization schemes

This work reports on the performances of the hyperquantization algorithm in the symmetric hyperspherical coordinate representation for the F + H-2 reaction. The use of alternative sequential diagonalization schemes has greatly reduced the computing time and memory requirements, making the technique very efficient and competitive for applications to atom-diatom reactions for the entire range of hyperradial variable rho. The effectiveness of the sequential diagonalization-truncation depends on the topology of the potential energy surface, which varies along different ranges of the hyperradius. The appearance at rho approximate to 4 a(0) of the ridge line on the potential energy surface, which separates the reactant and product valleys, marks the transition between the regions of preferential applicability of two alternative ways to perform sequentially the diagonalization of the fixed-rho Hamiltonian matrix. Reaction probabilties for total zero angular momentum are reported and compared with previous calculations.