Predissociation resonances from the complex eigenvalue Schrodinger equation

The authors present a state-specific, complex eigenvalue approach to the calculation of molecular predissociation resonances. The theory employs correlated electronic wavefunctions and related coupling matrix elements computed on the real coordinate axis. Only the nuclear Gamow orbital along the fragmentation coordinate is complexified. Application to the predissociation of the nu =0, J=0 level of the A2 Sigma + state of HeH has yielded a width of 2.9 cm-1, in excellent agreement with the recently reported experimental value of 3.1+or-1.0 cm-1.