Abstract

The interaction of molecules with radiation can lead to metastable electronic states that decay non-radiatively by emission of electrons. This includes high-energy processes such as Auger decay [1] of core-ionized states, where electrons with energies of hundreds or even thousands of electron volts are emitted, as well as low-energy processes such as Coster-Kronig decay [2] and interatomic/intermolecular Coulombic decay,[3] where the emitted electrons have energies of a few or even less than one electron volt.

The theoretical modeling of nonradiative decay is difficult because the initial states are embedded in the ionization continuum and not L2-integrable. An elegant approach to decaying states is afforded by complex scaling and the method of complex basis functions,[4,5] which produce Hamiltonians with complex eigenvalues from which total and partial decay widths can be extracted. Our numerical results indicate that complex-scaled coupled-cluster theory and Møller-Plesset perturbation theory are well suited for a broad range of autoionization phenomena.[6–10]

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[2] D. Coster and R. Kronig, Physica, 2 (1935), 13.

[3] L.S. Cederbaum, J. Zobeley, F. Tarantelli, Phys. Rev. Lett. 79 (1997), 4778.

[4] C.W. McCurdy and T.N. Rescigno, Phys. Rev. Lett. 41 (1978), 1364.

[5] A.F. White, M. Head-Gordon, C.W. McCurdy, J. Chem. Phys. 142 (2015), 054103.

[6] F. Matz and T.-C. Jagau, J. Chem. Phys. 156 (2022), 114117.

[7] F. Matz and T.-C. Jagau, Mol. Phys. 121 (2023), e2105270.

[8] N.K. Jayadev, A. Ferino-Pérez, F. Matz, A.I. Krylov, T.-C. Jagau, J. Chem. Phys. 158 (2023), 064109.

[9] A. Ferino-Pérez and T.-C. Jagau, J. Phys. Chem. A 128 (2024), 3957.

[10] J.P. Drennhaus, A. Ferino-Pérez, F. Matz, and T.-C. Jagau, Phys. Chem. Chem. Phys., accepted (2024). DOI: 10.1039/D4CP02085E