Dissociative Electron Attachment to HCN, HCCH and HCCCN

Studies of polyatomic molecules show that more than one degree of freedom comes into play in the dissociative process of certain molecules upon low-energy electron collision. In many of these cases, bond breaking may only proceed if the initial symmetry of the target molecule is distorted. We have performed a multi-dimensional computational treatment of the dissociative electron attachment (DEA) to three polyatomic systems, HCN, HCCH, and HCCCN below 10 eV and compared their nuclear motion and dissociation cross section. We further investigated the isotope effect in the case of HCN and HCCH. We have adopted the same computational approach in the study of these systems. This approach consists of time-dependent wavepacket propagation where the Hamiltonian operator involves the multi-dimensional complex potential energy surfaces (PESs) of the resonant anion.