Multiplet-specific shape resonant features in photoionization of NO

Abstract

We report photoionization cross sections and asymmetry para~eters for t~e 5u and 4u levels of NO obtained using numerical photoelectron contmuum funct10ns. For the Su orbital multiplet-specific potentials lead to shape-resonant cross sections which show significant nonstatistical multiplet behavior. This behavior, which reflects the sensitivity of shape resonances to the exchange component of the molecular ion potential, is most prominently characterized by resonance peaks at substantially different photoelectron kinetic energies in the two multiplet channels. Comparison of the calculated cross sections with available experimental data for NO shows somewhat poorer agreement than has been seen in the photoionization of closed-shell systems such as N 2 and CO. This difference reflects the more complex nature of photoionization processes in open-shell molecules.

Streaking single-electron ionization in open-shell molecules driven by X-ray pulses

“…This partially filled 2π orbital is what leads to singlet and triplet states of the molecular ion after ionization. For a singlet state of the molecular ion between the i and 2π orbitals, the wavefunction of the molecular ion and the continuum electron is given by the following linear combination of Slater de-terminants [21]…”

“…Indeed, following ionization, for closed-shell molecules, the final molecular ion is in a doublet spin state. For open-shell molecules, the final molecular ion is in a singlet or triplet spin state, that is, the total spin of the open-shell orbital and the orbital where the electron ionizes from is zero or one [21].…”

Photoionization cross sections and asymmetry parameters for silane

“…This procedure has proven to be numerically robust and capable of providing a quantitative description of the photoionization dynamics in molecular systems studied to date. [23][24][25][26] Although this method was developed in the early eighties for photoionization studies of linear systems, 23,24 it has been extended to nonlinear polyatomic molecules 25,26 and still constitutes one of a few tools for carrying out ab initio calculations of cross sections and asymmetry parameters for photoionization of such systems. The comparison between the calculated results, even in the exact static-exchange ͑SE͒ level, with the experimental data would provide information on the role played by important physical effects, e.g., target electronic correlation, multichannel coupling, correlation-polarization effects, etc., not included in the calculations.…”

4σ−1Inner Valence Photoionization Dynamics of NO Derived from Photoelectron-Photoion Angular Correlations

“…While the dipole transition moment ratios are the result of the fit, the absolute transition cross sections given in Table I were derived using the absolute cross sections of the 4s 21 photoline measured by Gustaffson et al [29] for normalization. The extrapolation from their high-est 40 eV to our 40.8 eV photon energy was done using the calculations of Smith et al [30]. The phase differences are shifted to d ss 0.…”