Probabilities for the F+H-2 -> 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 rea ction. The use of alternative sequential diagonalization schemes has greatl y reduced the computing time and memory requirements, making the technique very efficient and competitive for applications to atom-diatom reactions fo r the entire range of hyperradial variable rho. The effectiveness of the se quential diagonalization-truncation depends on the topology of the potentia l energy surface, which varies along different ranges of the hyperradius. T he appearance at rho approximate to 4 a(0) of the ridge line on the potenti al energy surface, which separates the reactant and product valleys, marks the transition between the regions of preferential applicability of two alt ernative ways to perform sequentially the diagonalization of the fixed-rho Hamiltonian matrix. Reaction probabilties for total zero angular momentum a re reported and compared with previous calculations.