Photoionization of water molecules by high energy photons

Abstract

We theoretically study the photoionization of water molecules by high energy photon impact. We develop a model in which the final state wavefunction is given by a Coulomb continuum wavefunction with effective charges and the water molecule bound states are represented using the Moccia's monocentric wavefunctions. We obtain analytical expressions for the transition matrix element that enable the computation of cross sections by numerical quadratures. We compare our predictions for photon energies between 20 and 300 eV with more elaborated theoretical results and experiments. We obtain a very good agreement with experiments, in particular, at enough high energies where there is a lack of elaborated results due to their high computational cost.

Different approximations in the polarization control of two-color water molecule ionization

“…The CC wavefunction takes into account the Coulomb interaction of the electron with the residual target in the final channel of the reaction. It has been shown that this interaction must be included to describe the photoionization reaction with neutral targets in the correct manner [20][21][22][23][24].…”

Interferences in the photoionization of water molecules

“…In figures 4 and 5, we present results for the 3a 1 and 1b 2 orbitals, respectively, that are expected to present three-center interference effects considering their ligand character. As a fact, we observe in figures 4(a) and 5(a) that the molecular cross sections as a function of the energy present deviations from effective atomic ones obtained with the CNDO approximation (17) as the photon energy increases. These differences may be attributed to the coherent emission from the centers of the molecule.…”

“…The final wavefunction of the CC model (2) takes into account the Coulomb interaction of the electron with the residual target in the final channel of the reaction. It was shown that this interaction must be included for to describe the photoionization reaction with neutral targets in a proper way [1,17,20,21]. The choice Z 1 ef = corresponds to the asymptotic value of the residual target charge at sufficiently large distances from the target.…”

“…Recently, we performed total cross sections calculations for several orbitals of the water molecules [17]. We developed a first order model describing the bound states by using monocentric Moccia's wavefunctions.…”