Accurate representation of the continuum orbital in a Gaussian basis set: application to Auger decay rates
Abstract
Many processes in chemistry and physics, such as autoionization, photoionization, or electron-impact collisions, involve unbound electrons. Despite their importance, theoretical methods for modeling continuum electrons remain significantly less developed than those for purely bound electronic states. Here we present a novel approach for treating continuum electrons within Gaussian-based quantum chemistry. The method represents continuum orbital in a discrete basis of standard Gaussian-type orbitals (GTOs), where the continuum wave function is obtained by solving the Lippmann-Schwinger equation with proper boundary conditions using an analytical representation of the Green's function in an auxiliary GTO basis set. The resulting continuum orbital is multicentered and multichannel, providing a rigorous description of scattering states. As an initial application of the new methodology, we compute Auger decay rates for several atomic and molecular systems, including Ne, H2O, CO2, and Ar. We demonstrate a consistent improvement of the results with increasing the quality of the continuum representation. We show also that higher-order electron-correlation effects in the bound domain are essential for an accurate treatment of satellite transitions. The present formalism therefore provides a systematically improvable Gaussian-based framework for continuum-electron problems that is fully compatible with standard quantum chemistry methods.
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BibTeX
@misc{mahato2026accurate,
title = {{Accurate representation of the continuum orbital in a Gaussian basis set: application to Auger decay rates}},
author = {Dibyendu Mahato and Saikat Roy and Wojciech Skomorowski},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04202},
eprint = {2611.04202},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04202},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Accurate representation of the continuum orbital in a Gaussian basis set: application to Auger decay rates
AU - Dibyendu Mahato
AU - Saikat Roy
AU - Wojciech Skomorowski
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04202
UR - https://arxiv.org/abs/2611.04202
AB - Many processes in chemistry and physics, such as autoionization, photoionization, or electron-impact collisions, involve unbound electrons. Despite their importance, theoretical methods for modeling continuum electrons remain significantly less developed than those for purely bound electronic states. Here we present a novel approach for treating continuum electrons within Gaussian-based quantum chemistry. The method represents continuum orbital in a discrete basis of standard Gaussian-type orbitals (GTOs), where the continuum wave function is obtained by solving the Lippmann-Schwinger equation with proper boundary conditions using an analytical representation of the Green's function in an auxiliary GTO basis set. The resulting continuum orbital is multicentered and multichannel, providing a rigorous description of scattering states. As an initial application of the new methodology, we compute Auger decay rates for several atomic and molecular systems, including Ne, H_2O, CO_2, and Ar. We demonstrate a consistent improvement of the results with increasing the quality of the continuum representation. We show also that higher-order electron-correlation effects in the bound domain are essential for an accurate treatment of satellite transitions. The present formalism therefore provides a systematically improvable Gaussian-based framework for continuum-electron problems that is fully compatible with standard quantum chemistry methods.
ER -