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

Solange Mariel Di Napoli; Alexei Nefedov; María Andrea Barral; Gustavo E. Murgida; Ana María Llois; Christof Wöll; M. Verónica Ganduglia-Pirovano; Verónica Laura Vildosola

arXiv · 2607.28797

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

Solange Mariel Di Napoli·Alexei Nefedov·María Andrea Barral·Gustavo E. Murgida·Ana María Llois·Christof Wöll·M. Verónica Ganduglia-Pirovano·Verónica Laura Vildosola

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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 UO$_2$(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/UO$_2$(111) as a stringent benchmark for electronic-structure methods describing open-shell molecule-surface interactions.

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Solange Mariel Di Napoli, Alexei Nefedov, María Andrea Barral, Gustavo E. Murgida, Ana María Llois, Christof Wöll, M. Verónica Ganduglia-Pirovano, Verónica Laura Vildosola. 2026-07-30. Open-Shell Molecules as Sensitive Probes of Spin-Orbit-Controlled Surface Electronic Structure. https://arxiv.org/abs/2607.28797

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