1 research outputs found
High-Energy Molecular-Frame Photoelectron Angular Distributions: A Molecular Bond-Length Ruler
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