Dissociative Electron Attachment in C2H via Electronic Resonances

Abstract

<div> <div> <div> <div> <p>Investigation of microwave-activated CH<sub>4</sub>/H<sub>2 </sub>plasma used in chemical vapor deposition of diamond revealed the presence of electronically excited C<sub>2</sub><sup>-</sup>(B<sup>2</sup>Σ<sub>u</sub><sup>+</sup>). Using high-level electronic structure methods, we investigate electronic structure of C<sub>2</sub>H<sup>-</sup> and suggest possible routes for formation of C<sub>2</sub><sup>-</sup> in the ground (X<sup>2</sup>Σ<sub>g</sub><sup>+</sup>) and excited (B<sup>2</sup>Σ<sub>u</sub><sup>+</sup>) states via electronic resonances. To describe electronically meta-stable states, we employ the equation-of-motion coupled-cluster method augmented by the complex absorbing potential. The resonance wave-functions are analyzed using natural transition orbitals. We identified several resonances in C<sub>2</sub>H<sup>-</sup>, including the state that may lead to C<sub>2</sub><sup>-</sup>(B<sup>2</sup>Σ<sub>u</sub><sup>+</sup>). </p><p> </p> <p></p><p> </p> <p> </p> <p> </p> </div> </div> </div> </div>