TY  - JOUR
AU  - Haags, Anja
AU  - Brandstetter, Dominik
AU  - Yang, Xiaosheng
AU  - Egger, Larissa
AU  - Kirschner, Hans
AU  - Gottwald, Alexander
AU  - Richter, Mathias
AU  - Koller, Georg
AU  - Bocquet, François C.
AU  - Wagner, Christian
AU  - Ramsey, Michael G.
AU  - Soubatch, Serguei
AU  - Puschnig, Peter
AU  - Tautz, F. Stefan
TI  - Tomographic identification of all molecular orbitals in a wide binding-energy range
JO  - Physical review / B
VL  - 111
IS  - 16
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2025-02241
SP  - 165402
PY  - 2025
AB  - 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 𝜋 and 23 𝜎 orbitals from the experimental data of the prototypical organic molecule bisanthene (C28⁢H14) 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001460182600007
DO  - DOI:10.1103/PhysRevB.111.165402
UR  - https://juser.fz-juelich.de/record/1041428
ER  -