We conduct first-principles simulations of La3Ni2O7, a nickelate in which recent experiments have shown signs of high-temperature superconductivity. Within the hydrostatic pressure range where superconductivity is observed, we find a significant increase in effective on-site repulsion in the maximally localised Wannier functions comprising the Ni eg bands crossing the Fermi energy. We attribute this increase to an interplay between orbital localisation and competing screening channels arising from structural variations. Our results indicate that the superconducting region in the La3Ni2O7 phase diagram coincides with a region of enhanced electronic correlations, which show a close correspondence with the critical temperature. Including finite temperatures up to 100 K, abinitio molecular dynamics simulations then provide new insights into the debated structural phase diagram and further clarify the origin of the right-triangular superconducting dome. Finally, we study Ac3Ni2O7 to confirm the crucial role of the A-site cation in shaping the pressure-driven evolution of electronic correlations.
@article{arxiv.2502.19501,
title = {First-Principles Evidence for Strongly Correlated Superconductivity Driven by Structural Variations in La$_3$Ni$_2$O$_7$},
author = {Daan Verraes and Tom Braeckevelt and Nick Bultinck and Veronique Van Speybroeck},
journal= {arXiv preprint arXiv:2502.19501},
year = {2026}
}