Optimal transition states for polaron hopping transport without supercells
Abstract
Polaron formation localizes charge carriers and drives a crossover from band-like to hopping transport in materials. Hopping dynamics can be obtained from DFT supercell calculations of transition states, but these suffer from polaron self-interaction, spurious electrostatics, and poor scaling with polaron size. We introduce a supercell-free framework for ab initio polaron hopping transport based on the ab initio polaron equations formalism, its variational formulation, and the string method. The approach avoids explicit real-space DFT supercell calculations: it optimizes transition states directly in reciprocal space and provides the polaron configurations along the path, enabling the evaluation of adiabatic hopping rates and mobilities. We apply the method to LiF and rutile TiO2, revealing multi-step and anisotropic hopping mechanisms. In rutile TiO2, we compare the computed electron-polaron mobility with experiments and with alternative first-principles approaches. Our results establish a scalable route to first-principles polaron-hopping dynamics in materials in which charge motion is governed by self-trapping.
Related
- Investigation of Hopping Conduction and Its Impact on the Subthreshold and Transition Region Transport in Oxide Semiconductor Transistors by Magneto-Transport Measurements
- Trust-Limited Machine-Learning-Accelerated Nudged Elastic Band Calculations for Small-Polaron Hopping in Rutile TiO2
- Nonadiabatic polaron dynamics from machine-learned hopping trajectories
- Transport Signatures of a Kinetically Self-Trapped Nagaoka Polaron
- Controlling transport with structured long-range hopping
BibTeX
@misc{vasilchenko2026optimal,
title = {{Optimal transition states for polaron hopping transport without supercells}},
author = {Vasilii Vasilchenko and Matteo Giantomassi and Samuel Poncé and Xavier Gonze},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.18096},
eprint = {2607.18096},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.18096},
}
RIS
TY - UNPB
TI - Optimal transition states for polaron hopping transport without supercells
AU - Vasilii Vasilchenko
AU - Matteo Giantomassi
AU - Samuel Poncé
AU - Xavier Gonze
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2607.18096
UR - https://arxiv.org/abs/2607.18096
AB - Polaron formation localizes charge carriers and drives a crossover from band-like to hopping transport in materials. Hopping dynamics can be obtained from DFT supercell calculations of transition states, but these suffer from polaron self-interaction, spurious electrostatics, and poor scaling with polaron size. We introduce a supercell-free framework for ab initio polaron hopping transport based on the ab initio polaron equations formalism, its variational formulation, and the string method. The approach avoids explicit real-space DFT supercell calculations: it optimizes transition states directly in reciprocal space and provides the polaron configurations along the path, enabling the evaluation of adiabatic hopping rates and mobilities. We apply the method to LiF and rutile TiO_2, revealing multi-step and anisotropic hopping mechanisms. In rutile TiO_2, we compare the computed electron-polaron mobility with experiments and with alternative first-principles approaches. Our results establish a scalable route to first-principles polaron-hopping dynamics in materials in which charge motion is governed by self-trapping.
ER -