Photoionization of the CO and NO molecules

Abstract

We present photoionization cross sections for two diatomic molecules, CO and NO, using a distorted-wave approximation. Both CO and NO are important atmospheric molecules, particularly in shock-heated atmospheres and in some astrophysical contexts. Photoionization cross sections may be used to compute the bound–free absorption contribution, which although less relevant than the bound–bound absorption that dominates in the near infra-red wavelength band, is still necessary for a complete description of molecular absorption. A configuration-average distorted-wave method is used to compute the photoionization cross sections based on earlier molecular structure tabulations. Our calculations are compared to experiment and good agreement is found at incident energies above 40 eV.

Photon and electron ionization of the HeH+ Molecule

“…The configuration-average distorted-wave (CADW) method [5] has been found to be quite useful in calculating both photon and electron ionization cross sections of diatomic molecules. Calculations using the CADW method were recently made for the photon ionization of CO [6] and were found to be in good agreement with time of flight spectrometer measurements [7], and also for the photon ionization of NO [6] which were also found to be in good agreement with time of flight spectrometer measurements [8]. Calculations using the CADW method were recently made for the electron ionization of CN + [9] and were found to be in fairly good agreement with crossedbeams measurements [10].…”

Electron and photon ionization of the BeH molecule

“…We note that configuration-average photon ionization cross sections for λ¹0 are slightly different from those for λ=0 [10].…”

“…where again w is the occupation number of the active subshell and nlλ and ò e l e λ e are quantum numbers of the valence bound electron and the ejected electron. The configuration-average photon ionization cross section for λ=0 is given by [10]: , ω is the radiation field frequency, and c is the speed of light. The total configuration-average photon ionization cross section is given by:…”

“…In this paper we use the CADW method to calculate electron ionization cross sections of BeH to check previous Deutsch-Mark (DM) and binary encounter Bethe (BEB) calculations [8]. We note that calculations using the CADW method have also been made for the photon ionization of C 2 [9], CO [10], and NO [10]. As an overall check, we use the CADW method to calculate photon ionization cross sections of BeH to compare with previous molecular-adapted quantum defect orbital (MQDO) calculations [11].…”

A high level theory investigation on the lowest-lying ionization potentials of glycine (NH2CH2COOH)

“…It is well known that a significant number of IPs from various outermost molecular valence orbitals are required for adequately describing several photon-driven related quantities (such as theoretical photoionization cross sections). 69,70 In this sense, Tanaka et al 32 used the four outermost molecular valence orbitals for probing the photoionization cross sections for the formaldehyde molecule and highlighted that taking into account the electronic correlation in the target wave function (specially in terms of the more inner orbitals) would yield better agreement of both the dipole length and velocity in regards to the experimental data. Therefore, the twelve lowest-lying vertical IPs for the six conformations of the NH 2 CH 2 COOH molecule have been computed using the EOMIP-CCSD approach along with the AVDZ and AVTZ basis sets; the whole set of results can be found in Table S1 in the ESI †…”