Abstract
Double Core-Hole (DCH) states of small molecules are assessed with the restricted active space self-consistent field and multi-state restricted active space perturbation theory of second order approximations. To ensure an unbiased description of the relaxation and correlation effects on the DCH states, the neutral ground-state and DCH wave functions are optimized separately, whereas the spectral intensities are computed with a biorthonormalized set of molecular orbitals within the state-interaction approximation. Accurate shake-up satellite binding energies and intensities of double-core-ionized states (K−2) are obtained for H2O, N2, CO, and C2H2n (n = 1–3). The results are analyzed in detail and show excellent agreement with recent theoretical and experimental data. The K−2 shake-up spectra of H2O and C2H2n molecules are here completely characterized for the first time.
Original language | English |
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Article number | 131101 |
Journal | Journal of Chemical Physics |
Volume | 155 |
Issue number | 13 |
Number of pages | 10 |
ISSN | 0021-9606 |
DOIs | |
Publication status | Published - 2021 |