Vibrational Feshbach resonances in electron attachment to carbon dioxide clusters

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

“…Application of the simple spherical model for the electron binding energies E B , sketched in Section C.2, reproduces the redshifts when -in contrast to the situation for N 2 O clusters -attractive short range potentials are used (Leber et al, 2000b;Barsotti et al, 2002a). Figure 47 shows calculated electron binding energies to clusters with N ¼ 4 À 22 (dashed curves), as obtained with realistic choices of the short range potential U 0 (for further results see Leber et al (2000b)).…”

“…Previous experimental work of cluster anion formation in energycontrolled electron collisions with carbon dioxide clusters includes low-resolution beam studies over extended energy ranges (Compton, 1980, Stamatovic et al, 1985aKnapp et al, 1985Knapp et al, , 1986a, investigations by Rydberg electron transfer (RET) (Kondow, 1987;Kraft et al, 1989Kraft et al, , 1991Misaizu et al, 1991) and the recent LPA studies (energy width about 1 meV) (Leber et al, 2000b;Barsotti et al, 2002a). Anion mass spectra obtained by RET revealed an intriguing anion cluster size dependence.…”

“…Figure 47 shows calculated electron binding energies to clusters with N ¼ 4 À 22 (dashed curves), as obtained with realistic choices of the short range potential U 0 (for further results see Leber et al (2000b)). For comparison, the experimentally derived binding energies E B,exp for the (010), (020)/(100), (030)/(110) and (040)/(120)/(200) resonance series, as calculated from the center-of-gravity resonance positions E R through E B,exp ¼ E R À E q , are included, using two different assumptions: (a) N ¼ q and (b) N ¼ q þ 1.…”

Electron attachment to molecules in a cluster environment

“…This approximation does not allow formation of weakly bound states due to the long-range interaction that might lead to formation of vibrational Feshbach resonances. [27][28][29] However, these states are very delocalized and extend beyond the cluster region. They usually lead to the process of intermolecular vibrational energy redistribution and formation of the parent negative ion (nondissociative attachment).…”

“…This effect was observed in small methyl iodide clusters 30 and mediumsize CO 2 and N 2 O clusters. 27,28 This change in VAE depends very weakly on the molecular geometry, therefore we adopt the approach used before in the treatment of attachment to physisorbed molecules 31,32 and molecular clusters, 30 and change VAE by a uniform shift E VAE of the anion curve.…”