Bridging from First Principles to Experimental Timescales: A Framework for Multi-Scale Quadrupolar NMR Simulations

ChemRxiv

Abstract

Solid-state Nuclear Magnetic Resonance (NMR) is a powerful experimental tool for understanding ion transport in battery materials. Yet, dynamical averaging often leads to mixing of structural and dynamic information and prohibits spectral interpretation. Computational approaches historically fail to match the time-and length scales needed to compare with experiment. We present a multi-scale framework simulating quadrupolar NMR spectra at experimental timescales with ab initio accuracy. By combining machine-learned electric field gradients with molecular dynamics and kinetic Monte Carlo, we overcome intrinsic timescale limitations, enabling simulations with thousands of atoms for a time scale of milliseconds. Using the battery material lithium titanate spinel (Li4Ti5O12; LTO) as a model system, we simulate spectra across dynamical regimes from static to fast diffusion, showing good agreement with experimental data. The framework captures realistic ion dynamics and structural disorder. Overall, this approach can aid in detailed interpretation of experimental spectra, reducing reliance on heuristic assignments.

Authors 6

1. Tabea Huss

   Fritz Haber Institute of the Max Planck Society

   Affiliation as printed

   Fritz-Haber-Institute of the Max Planck Society

2. Vera Michaela Barysch Aachen Institute of Technical and Macromolecular Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich GmbH

   Institute of Energy Technologies (IET-1

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University

3. Josef Granwehr Aachen Institute of Technical and Macromolecular Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich GmbH

   Institute of Energy Technologies (IET-1

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University

4. Karsten Reuter

   Fritz Haber Institute of the Max Planck Society

   Affiliation as printed

   Fritz-Haber-Institute of the Max Planck Society

5. Christoph Scheurer

   Forschungszentrum Jülich · Fritz Haber Institute of the Max Planck Society

   Affiliation as printed

   Forschungszentrum Jülich GmbH

   Fritz-Haber-Institute of the Max Planck Society

   Institute of Energy Technologies (IET-1

6. S. Kocher

   Forschungszentrum Jülich · Fritz Haber Institute of the Max Planck Society

   Affiliation as printed

   Forschungszentrum Jülich GmbH

   Fritz-Haber-Institute of the Max Planck Society

   Institute of Energy Technologies (IET-1