Inner-shell photodetachment of Cn− ions

Abstract

We present a theoretical study of K-shell photodetachment of C − 2 and C − 3 ions. The calculations were carried out using the complex Kohn variational method. Our study addresses the recent observation that what appears as a single, narrow shape resonance close to threshold in the K-shell photodetachment of C − splits into several peaks in the longer C − n carbon anion chains, with the number of peaks increasing with increasing n-values. We argue that the number of expected peaks is related to the number of symmetry-equivalent carbon atoms.

Vibrationally Resolved Inner‐Shell Photoexcitation of the Molecular Anion C2−

“…The cross section exhibits two resonance features, one ∼4.5 eV below this threshold and one ∼1.4 eV above. These two features were already observed in the experimental data communicated by Berrah and Bilodeau to Douguet et al [45] . These data were measured at a similar photon‐energy spread as in the present overview scan.…”

“…The main panel of Figure 1 provides an overview over the PDD cross section in the vicinity of the C 2 − $${1\sigma }$$ ionization threshold which has been theoretically predicted at 284.1 eV [45] . The cross section exhibits two resonance features, one ∼4.5 eV below this threshold and one ∼1.4 eV above.…”

Vibrationally Resolved Inner-Shell Photoexcitation of the Molecular Anion C$_2^-$

“…The main panel of Figure 1 provides an overview over the PDD cross section in the vicinity of the C − 2 1σ ionization threshold which has been theoretically predicted at 284.1 eV [45] . The cross section exhibits two resonance features, one ∼4.5 eV below this threshold and one ∼1.4 eV above.…”

“…The cross section for C − 2 photodetachment has been calculated previously by Douguet et al [45] who considered only the strong above-threshold resonance. The red full line in the right inset of Figure 1 displays their result, scaled to the present experimental cross section and shifted by -0.1 eV on the photon-energy axis.…”

“…We used a sufficiently high photon-energy resolving power that allowed us to resolve transitions between individual vibrational levels, thus providing detailed insight into the highly correlated nuclear and electronic relaxation dynamics, that sets in after the initial creation of a C 1s core hole. Previous work on inner-shell photoabsorption by molecular anions was either confined to inner-valence shells [42,43] or, for photoabsorption by K-shell electrons, used rather low photon-energy resolving powers [44,45] .…”