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Non-adiabatic quantum molecular dynamics: Ionization of many electron systems

Mathias Uhlmann·Thomas Kunert·Ruediger Schmidt
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Abstract

We propose a novel method to describe realistically ionization processes with absorbing boundary conditions in basis expansion within the formalism of the so-called Non-Adiabatic Quantum Molecular Dynamics. This theory couples self-consistently a classical description of the nuclei with a quantum mechanical treatment of the electrons in atomic many-body systems. In this paper we extend the formalism by introducing absorbing boundary conditions via an imaginary potential. It is shown how this potential can be constructed in time-dependent density functional theory in basis expansion. The approach is first tested on the hydrogen atom and the pre-aligned hydrogen molecular ion H2+ in intense laser fields where reference calculations are available. It is then applied to study the ionization of non-aligned H2+ and H2. Striking differences in the orientation dependence between both molecules are found. Surprisingly, enhanced ionization is predicted for perpendicularly aligned molecules.

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Mathias Uhlmann, Thomas Kunert, Ruediger Schmidt. 2005-09-16. Non-adiabatic quantum molecular dynamics: Ionization of many electron systems. https://doi.org/10.1088/0953-4075/39/14/007

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