Symmetry- and multiplet-resolved N1sphotoionization cross sections of theNO2molecule

Abstract

We present a joint theoretical and experimental investigation of the N 1s photoionization of NO 2 in the shape resonance region. The theoretical calculations, based on a single-channel relaxed-core Hartree-Fock approximation, predict that the shape resonance appears only in the A 1 → B 2 transition and that the shape resonance energy of the N 1s −1 1 A 1 channel is about 2.6 eV lower in kinetic energy than that of the N 1s −1 3 A 1 channel, suggesting that the potential for the 1 A 1 channel is much more attractive than that for the 3 A 1 channel. Symmetry-selected cross sections measured by means of a multiple-ion coincidence imaging prove that the shape resonance appears only in the A 1 → B 2 transition, as predicted by the calculation. The experimental partial cross sections for the N 1s −1 1 A 1 and 3 A 1 channels measured by means of conventional electron spectroscopy exhibit the shape-resonance maxima at photon energies of 416.3 and 415.9 eV, respectively, at corresponding kinetic energies of 3.0 and 3.3 eV, respectively, implying that the attractive potential for the 1 A 1 channel is overestimated in the single-channel approximation. The possible role played by correlation effects on the K-shell ionization of NO 2 is discussed in terms of interchannel coupling between the main-line channels and, possibly, with additional excited target states.

N 1s photoelectron angular distributions from fixed-in-space NO2 molecules: Stereodynamics and symmetry considerations

“…3͑a͒ shows, shape resonance occurs only for the transition to b 2 final state, which is consistent with the results of previous experimental and theoretical work. The energy dependence of ␤ in this study agrees qualitatively with that by Saito et al, 39 although the present ␤ values change more rapidly as the energy increases. 3.5 eV͒ of the shape resonance, although the calculated profile is significantly sharper because nuclear motion and core-hole relaxation effects are not considered in these calculations.…”

“…3 together with the present experimental results of ␤ at selected KEs. 39 Present DFT calculations well reproduce the peak position ͑ca. 3͑a͒ shows, shape resonance occurs only for the transition to b 2 final state, which is consistent with the results of previous experimental and theoretical work.…”

“…38,39 The shape resonance appears around 416.43 eV, 38 which is about 3.8 eV above the triplet ͑ 3 A 1 ͒ ionization threshold and about 3.1 eV above the singlet ͑ 1 A 1 ͒ ionization threshold. 38,39 The shape resonance appears around 416.43 eV, 38 which is about 3.8 eV above the triplet ͑ 3 A 1 ͒ ionization threshold and about 3.1 eV above the singlet ͑ 1 A 1 ͒ ionization threshold.…”

Molecular frame and recoil frame photoelectron angular distributions from dissociative photoionization of NO2

“…The experimental technique was the vector correlation method, where the velocity vectors of the photoelectron and the recoil ionic fragment produced for each dissociative ionization event were measured, leading to the RFPADs. 31,49 Further developments 49 will tackle the question of the information which can be obtained by comparing the RFPADs and MFPADs in multiple ionization of small polyatomic molecules, with respect to the validity or the breakdown of the axial recoil approximation. 47 The theoretical MFPADs and RFPADs were computed using a relatively simple static-exchange plus model polarization one-electron interaction potential.…”

“…There have been theoretical studies of the photoelectron spectrum. 31 The outline of the paper is as follows: In Sec. 30 In addition there has been one theoretical study on photoionization dynamics.…”