Efficient polynomial expansion of the scattering Greenrsquo;s function: Application to the D+H2(v=1) rate constant

摘要

We apply the absorbing boundary condition (ABC) discrete variable representation (DVR) theory of quantum reactive scattering to the initial state selected D+H2(v=1,thinsp;j)rarr;DH+H reaction. The ABChyphen;DVR Greenrsquo;s function is efficiently computed by a Newton polynomial expansion. We compute accurate reaction probabilities for the total energies and angular momenta required to obtain the thermal rate constantskv=1,thinsp;j(T). AtT=310 K, a thermal average overj=(0,1,2,3) is performed to yield the final resultkv=1(310 K)=1.87times;10minus;13cm3thinsp;moleculeminus;1thinsp;sminus;1, inquantitativeagreement with the most recent experimental value (1.9plusmn;0.2)times;10minus;13cm3thinsp;moleculeminus;1thinsp;sminus;1. TheJhyphen;shifting approximation using accurateJ=0 reaction probabilities is tested against the exact results. It reliably predictskv=1(T) for temperatures up to 700 K, but individual (v=1,thinsp;j) selected rate constants are in error by as much as 41percnt;.