| 2. | A. Haags, D. Brandstetter, X. Yang, L. Egger, H. Kirschner, A. Gottwald, M. Richter, G. Koller, F. C. Bocquet, C. Wagner, M. G. Ramsey, S. Soubatch, P. Puschnig, F. S. Tautz Tomographic identification of all molecular orbitals in a wide binding-energy range Journal Article In: Phys. Rev. B, vol. 111, no. 16, 2025, ISSN: 2469-9969. @article{Haags2025b,
title = {Tomographic identification of all molecular orbitals in a wide binding-energy range},
author = {A. Haags and D. Brandstetter and X. Yang and L. Egger and H. Kirschner and A. Gottwald and M. Richter and G. Koller and F. C. Bocquet and C. Wagner and M. G. Ramsey and S. Soubatch and P. Puschnig and F. S. Tautz},
doi = {10.1103/physrevb.111.165402},
issn = {2469-9969},
year = {2025},
date = {2025-04-00},
urldate = {2025-04-00},
journal = {Phys. Rev. B},
volume = {111},
number = {16},
publisher = {American Physical Society (APS)},
abstract = {<jats:p>In the past decade, photoemission orbital tomography (POT) has evolved into a powerful tool to investigate the electronic structure of organic molecules adsorbed on surfaces. Here we show that POT allows for the comprehensive experimental identification of all molecular orbitals in a substantial binding energy range of more than 10 eV. Making use of the angular distribution of photoelectrons as a function of binding-energy, we exemplify this by extracting an orbital-resolved projected density of states for 15 <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>π</a:mi></a:math> and 23 <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>σ</b:mi></b:math> orbitals from the experimental data of the prototypical organic molecule bisanthene (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:msub><c:mi mathvariant="normal">C</c:mi><c:mn>28</c:mn></c:msub><c:msub><c:mi mathvariant="normal">H</c:mi><c:mn>14</c:mn></c:msub></c:mrow></c:math>) on a Cu(110) surface. These experimental results for an essentially complete set of orbitals within the given binding-energy range serve as stringent benchmarks for electronic structure methods, which we illustrate by performing density functional calculations employing four frequently used exchange-correlation functionals. By computing the respective molecular-orbital-projected densities of states, a one-to-one comparison with experimental data for an unprecedented number of 38 orbital energies became possible. The quantitative analysis of our data reveals that the range-separated hybrid functional HSE performs best for the investigated organic/metal interface. At a more fundamental level, the remarkable agreement between the experimental and the Kohn-Sham orbital energies over a binding-energy range larger than 10 eV suggests that—perhaps unexpectedly—Kohn-Sham orbitals approximate Dyson orbitals, which would rigorously account for the electron extraction process in photoemission spectroscopy but are notoriously difficult to compute, in a much better way than previously thought.</jats:p>
<jats:sec>
<jats:title/>
<jats:supplementary-material>
<jats:permissions>
<jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement>
<jats:copyright-year>2025</jats:copyright-year>
</jats:permissions>
</jats:supplementary-material>
</jats:sec>},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
<jats:p>In the past decade, photoemission orbital tomography (POT) has evolved into a powerful tool to investigate the electronic structure of organic molecules adsorbed on surfaces. Here we show that POT allows for the comprehensive experimental identification of all molecular orbitals in a substantial binding energy range of more than 10 eV. Making use of the angular distribution of photoelectrons as a function of binding-energy, we exemplify this by extracting an orbital-resolved projected density of states for 15 <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>π</a:mi></a:math> and 23 <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>σ</b:mi></b:math> orbitals from the experimental data of the prototypical organic molecule bisanthene (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:msub><c:mi mathvariant="normal">C</c:mi><c:mn>28</c:mn></c:msub><c:msub><c:mi mathvariant="normal">H</c:mi><c:mn>14</c:mn></c:msub></c:mrow></c:math>) on a Cu(110) surface. These experimental results for an essentially complete set of orbitals within the given binding-energy range serve as stringent benchmarks for electronic structure methods, which we illustrate by performing density functional calculations employing four frequently used exchange-correlation functionals. By computing the respective molecular-orbital-projected densities of states, a one-to-one comparison with experimental data for an unprecedented number of 38 orbital energies became possible. The quantitative analysis of our data reveals that the range-separated hybrid functional HSE performs best for the investigated organic/metal interface. At a more fundamental level, the remarkable agreement between the experimental and the Kohn-Sham orbital energies over a binding-energy range larger than 10 eV suggests that—perhaps unexpectedly—Kohn-Sham orbitals approximate Dyson orbitals, which would rigorously account for the electron extraction process in photoemission spectroscopy but are notoriously difficult to compute, in a much better way than previously thought.</jats:p>
<jats:sec>
<jats:title/>
<jats:supplementary-material>
<jats:permissions>
<jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement>
<jats:copyright-year>2025</jats:copyright-year>
</jats:permissions>
</jats:supplementary-material>
</jats:sec> |
| 1. | A. Haags, D. Brandstetter, X. Yang, L. Egger, H. Kirschner, A. Gottwald, M. Richter, G. Koller, F. C. Bocquet, C. Wagner, M. G. Ramsey, S. Soubatch, P. Puschnig, F. S. Tautz Tomographic identification of all molecular orbitals in a wide binding energy range Journal Article Forthcoming In: ArXiv, Forthcoming. @article{Haags2025,
title = {Tomographic identification of all molecular orbitals in a wide binding energy range},
author = {A. Haags and D. Brandstetter and X. Yang and L. Egger and H. Kirschner and A. Gottwald and M. Richter and G. Koller and F. C. Bocquet and C. Wagner and M. G. Ramsey and S. Soubatch and P. Puschnig and F. S. Tautz},
url = {https://arxiv.org/abs/2501.05287},
year = {2025},
date = {2025-01-09},
urldate = {2025-01-09},
journal = {ArXiv},
abstract = {In the past decade, photoemission orbital tomography (POT) has evolved into a powerful tool to investigate the electronic structure of organic molecules adsorbed on surfaces. Here we show that POT allows for the comprehensive experimental identification of all molecular orbitals in a substantial binding energy range, in the present case more than 10 eV. Making use of the angular distribution of photoelectrons as a function of binding energy, we exemplify this by extracting orbital-resolved partial densities of states (pDOS) for 15 π and 23 σ orbitals from the experimental photoemission intensities of the prototypical organic molecule bisanthene (C28H14) on a Cu(110) surface. In their entirety, these experimentally measured orbital-resolved pDOS for an essentially complete set of orbitals serve as a stringent benchmark for electronic structure methods, which we illustrate by performing density functional theory (DFT) calculations employing four frequently-used exchange-correlation functionals. By computing the respective molecular-orbital-projected densities of states of the bisanthene/Cu(110) interface, a one-to-one comparison with experimental data for an unprecedented number of 38 orbital energies becomes possible. The quantitative analysis of our data reveals that the range-separated hybrid functional HSE performs best for the investigated organic/metal interface. At a more fundamental level, the remarkable agreement between the experimental and the Kohn-Sham orbital energies over a binding energy range larger than 10,eV suggests that -- perhaps unexpectedly -- Kohn-Sham orbitals approximate Dyson orbitals, which would rigorously account for the electron extraction process in photoemission spectroscopy but are notoriously difficult to compute, in a much better way than previously thought. },
keywords = {},
pubstate = {forthcoming},
tppubtype = {article}
}
In the past decade, photoemission orbital tomography (POT) has evolved into a powerful tool to investigate the electronic structure of organic molecules adsorbed on surfaces. Here we show that POT allows for the comprehensive experimental identification of all molecular orbitals in a substantial binding energy range, in the present case more than 10 eV. Making use of the angular distribution of photoelectrons as a function of binding energy, we exemplify this by extracting orbital-resolved partial densities of states (pDOS) for 15 π and 23 σ orbitals from the experimental photoemission intensities of the prototypical organic molecule bisanthene (C28H14) on a Cu(110) surface. In their entirety, these experimentally measured orbital-resolved pDOS for an essentially complete set of orbitals serve as a stringent benchmark for electronic structure methods, which we illustrate by performing density functional theory (DFT) calculations employing four frequently-used exchange-correlation functionals. By computing the respective molecular-orbital-projected densities of states of the bisanthene/Cu(110) interface, a one-to-one comparison with experimental data for an unprecedented number of 38 orbital energies becomes possible. The quantitative analysis of our data reveals that the range-separated hybrid functional HSE performs best for the investigated organic/metal interface. At a more fundamental level, the remarkable agreement between the experimental and the Kohn-Sham orbital energies over a binding energy range larger than 10,eV suggests that -- perhaps unexpectedly -- Kohn-Sham orbitals approximate Dyson orbitals, which would rigorously account for the electron extraction process in photoemission spectroscopy but are notoriously difficult to compute, in a much better way than previously thought. |
