English

Open-Shell Molecules as Sensitive Probes of Spin-Orbit-Controlled Surface Electronic Structure

Materials Science 2026-07-30 v1

Abstract

Open-shell molecules are highly sensitive probes of correlated oxide surfaces because their partially occupied frontier orbitals strongly amplify subtle changes in adsorbate-substrate hybridization. Combining infrared reflection-absorption spectroscopy with hybrid density functional theory including non-collinear magnetism and spin-orbit coupling, we show that inclusion of spin-orbit coupling is essential to reproduce the vibrational spectrum of NO adsorbed on UO2_2(111) by suppressing an otherwise artificial overhybridization between the NO frontier orbitals and uranium 5f states. While spin-orbit coupling determines the position of the N-O stretching and, dispersion-driven intermolecular interactions account for its asymmetric broadening at monolayer coverage. These results establish open-shell molecules as sensitive probes of spin-orbit-controlled surface electronic structure and identify NO/UO2_2(111) as a stringent benchmark for electronic-structure methods describing open-shell molecule-surface interactions.

Cite

@article{arxiv.2607.28797,
  title  = {Open-Shell Molecules as Sensitive Probes of Spin-Orbit-Controlled Surface Electronic Structure},
  author = {Solange Mariel Di Napoli and Alexei Nefedov and María Andrea Barral and Gustavo E. Murgida and Ana María Llois and Christof Wöll and M. Verónica Ganduglia-Pirovano and Verónica Laura Vildosola},
  journal= {arXiv preprint arXiv:2607.28797},
  year   = {2026}
}