Dissociative Electron Attachment to Acetylene

Experimental studies of electron impact on acetylene show the presence of a $\Pi$$^{*}$ resonance at 2.6 eV which leads to C$_{2}$H$^{-}$ + H. These fragements both have $\Sigma$ symmetry (C$_{2}$H$^{-}$, $^{1}$$\Sigma$; H, $^{1}$S), therefore, there must exist a curve crossing at bent geometries to explain these fragements. We performed electron scattering calculations using the complex Kohn variational method to determine the resonance parameters of this system. We discuss the mecanisms leading to dissociation into the product channels and report the computed cross sections. The results are then compared to available experimental findings. Work supported by NSF PHY-05-55401.