MP2-based composite extrapolation schemes can predict core-ionization energies for first-row elements with coupled-cluster level accuracy
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866913463865966592 |
|---|---|
| author | Morgunov, Anton Tran, Henry K. Meitei, Oinam Romesh Chien, Yu-Che Van Voorhis, Troy |
| author_facet | Morgunov, Anton Tran, Henry K. Meitei, Oinam Romesh Chien, Yu-Che Van Voorhis, Troy |
| contents | X-ray photoelectron spectroscopy (XPS) measures core-electron binding energies (CEBEs) to reveal element-specific insights into chemical environment and bonding. Accurate theoretical CEBE prediction aids XPS interpretation but requires proper modeling of orbital relaxation and electron correlation upon core-ionization. This work systematically investigates basis set selection for extrapolation to the complete basis set (CBS) limit of CEBEs from $Δ$MP2 and $Δ$CC energies across 94 K-edges in diverse organic molecules. We demonstrate that an alternative composite scheme using $Δ$MP2 in a large basis corrected by $Δ$CC-$Δ$MP2 difference in a small basis can quantitatively recover optimally extrapolated $Δ$CC CEBEs within 0.02 eV. Unlike $Δ$CC, MP2 calculations do not suffer from convergence issues and are computationally cheaper, and, thus, the composite $Δ$MP2/$Δ$CC scheme balances accuracy and cost, overcoming limitations of solely using either method. We conclude by providing a comprehensive analysis of the choice of small and large basis sets for the composite schemes and provide practical recommendations for highly accurate (within 0.10-0.15 eV MAE) ab initio prediction of XPS spectra. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_06364 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | MP2-based composite extrapolation schemes can predict core-ionization energies for first-row elements with coupled-cluster level accuracy Morgunov, Anton Tran, Henry K. Meitei, Oinam Romesh Chien, Yu-Che Van Voorhis, Troy Chemical Physics Quantum Physics X-ray photoelectron spectroscopy (XPS) measures core-electron binding energies (CEBEs) to reveal element-specific insights into chemical environment and bonding. Accurate theoretical CEBE prediction aids XPS interpretation but requires proper modeling of orbital relaxation and electron correlation upon core-ionization. This work systematically investigates basis set selection for extrapolation to the complete basis set (CBS) limit of CEBEs from $Δ$MP2 and $Δ$CC energies across 94 K-edges in diverse organic molecules. We demonstrate that an alternative composite scheme using $Δ$MP2 in a large basis corrected by $Δ$CC-$Δ$MP2 difference in a small basis can quantitatively recover optimally extrapolated $Δ$CC CEBEs within 0.02 eV. Unlike $Δ$CC, MP2 calculations do not suffer from convergence issues and are computationally cheaper, and, thus, the composite $Δ$MP2/$Δ$CC scheme balances accuracy and cost, overcoming limitations of solely using either method. We conclude by providing a comprehensive analysis of the choice of small and large basis sets for the composite schemes and provide practical recommendations for highly accurate (within 0.10-0.15 eV MAE) ab initio prediction of XPS spectra. |
| title | MP2-based composite extrapolation schemes can predict core-ionization energies for first-row elements with coupled-cluster level accuracy |
| topic | Chemical Physics Quantum Physics |
| url | https://arxiv.org/abs/2403.06364 |