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arXiv · 2105.11897

High-Energy Molecular-Frame Photoelectron Angular Distributions: A Molecular Bond-Length Ruler

Isabel Vela-Peréz·Fukiko Ota·Abir Mhamdi·Yoshiaki Tamura·Jonas Rist·Niklas Melzer·Safak Uerken·Giammarco Nalin·Nils Anders·Daehyun You·Max Kircher·Christian Janke·Markus Waitz·Florian Trinter·Renaud Guillemin·Maria Novella Piancastelli·Marc Simon·Vernon T. Davis·Joshua B. Williams·Reinhard Dörner·Keisuke Hatada·Kaoru Yamazaki·Kilian Fehre·Philipp V. Demekhin·Kiyoshi Ueda·Markus S. Schöffler·Till Jahnke
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Abstract

We present an experimental and theoretical study of core-level ionization of small hetero- and homo-nuclear molecules employing circularly polarized light and address molecular-frame photoelectron angular distributions in the light's polarization plane (CP-MFPADs). We find that the main forward-scattering peaks of CP-MFPADs are slightly tilted with respect to the molecular axis. We show that this tilt angle can be directly connected to the molecular bond length by a simple, universal formula. The extraction of the bond length becomes more accurate as the photoelectron energy is increased. We apply the derived formula to several examples of CP-MFPADs of C 1s and O 1s photoelectrons of CO, which have been measured experimentally or obtained by means of ab initio modeling. The photoelectron kinetic energies range from 70 to 1000~eV and the extracted bond lengths agree well with the known bond length of the CO molecule in its ground state. In addition, we discuss the influence of the back-scattering contribution that is superimposed over the analyzed forward-scattering peak in case of homo-nuclear diatomic molecules as N$_2$.

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Isabel Vela-Peréz, Fukiko Ota, Abir Mhamdi, Yoshiaki Tamura, Jonas Rist, Niklas Melzer, Safak Uerken, Giammarco Nalin, Nils Anders, Daehyun You, Max Kircher, Christian Janke, Markus Waitz, Florian Trinter, Renaud Guillemin, Maria Novella Piancastelli, Marc Simon, Vernon T. Davis, Joshua B. Williams, Reinhard Dörner, Keisuke Hatada, Kaoru Yamazaki, Kilian Fehre, Philipp V. Demekhin, Kiyoshi Ueda, Markus S. Schöffler, Till Jahnke. 2021-05-25. High-Energy Molecular-Frame Photoelectron Angular Distributions: A Molecular Bond-Length Ruler. https://doi.org/10.1039/d2cp05942h

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