Shape, feshbach, and "avoided crossing" resonances of the collinear F+DBr reaction

Exact quantum reaction probabilities for the collinear F+DBr(ν)→FD(ν′)+Br reaction yield a spectrum of resonances. Most but not all may be classified as familiar shape and Feshbach resonances, whereas the few exceptions are interpreted tentatively as novel "avoided crossing" resonances. As usual, the shape and Feshbach resonances represent quasibound complexes trapped in the wells of effective potentials, from where they decay by tunnelling and diabatic transitions. In contrast, avoided crossing resonances apparently arise from interference effects of two adiabatic potential curves at energies close to avoided crossings.