Hamiltonian learning reveals optoelectronic mechanisms across thermodynamic state space in soft semiconductors
Abstract
Predicting optoelectronic response across thermodynamic state space requires coupling finite-temperature nuclear dynamics to electronic structure at scales where direct first-principles calculations are impractical. Machine-learning force fields and Hamiltonian-learning models provide scalable predictions, but integrating them into reliable and interpretable workflows remains challenging. Here, we introduce FLOW-OTTER, a modular, model-agnostic framework that automates molecular dynamics, Hamiltonian prediction, observable extraction, reliability assessment, and Hamiltonian-level interpretation. We demonstrate FLOW-OTTER in halide perovskites, soft semiconductors whose anharmonic fluctuations strongly modulate electronic response. Using FLOW-OTTER, we show that independently learned nuclear and electronic models remain predictive when composed end-to-end, reproducing experimental temperature- and pressure-dependent band-gap trends using models trained only on first-principles targets at zero pressure. By resolving the nonlinear evolution of Pb-s/Br-p antibonding at the valence-band maximum, it identifies the microscopic origin of the asymmetric pressure response. FLOW-OTTER thus establishes Hamiltonian learning as a general route from thermodynamic trajectories to experimentally grounded optoelectronic mechanisms.
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BibTeX
@misc{vonhoff2026hamiltonian,
title = {{Hamiltonian learning reveals optoelectronic mechanisms across thermodynamic state space in soft semiconductors}},
author = {Frederik Vonhoff and Jesper R. Pedersen and Frederico P. Delgado and Martin Schwade and Peter Beck and Jonas A. Oldenstaedt and Ivano E. Castelli and David A. Egger},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.29361},
eprint = {2609.29361},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.29361},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Hamiltonian learning reveals optoelectronic mechanisms across thermodynamic state space in soft semiconductors
AU - Frederik Vonhoff
AU - Jesper R. Pedersen
AU - Frederico P. Delgado
AU - Martin Schwade
AU - Peter Beck
AU - Jonas A. Oldenstaedt
AU - Ivano E. Castelli
AU - David A. Egger
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.29361
UR - https://arxiv.org/abs/2609.29361
AB - Predicting optoelectronic response across thermodynamic state space requires coupling finite-temperature nuclear dynamics to electronic structure at scales where direct first-principles calculations are impractical. Machine-learning force fields and Hamiltonian-learning models provide scalable predictions, but integrating them into reliable and interpretable workflows remains challenging. Here, we introduce FLOW-OTTER, a modular, model-agnostic framework that automates molecular dynamics, Hamiltonian prediction, observable extraction, reliability assessment, and Hamiltonian-level interpretation. We demonstrate FLOW-OTTER in halide perovskites, soft semiconductors whose anharmonic fluctuations strongly modulate electronic response. Using FLOW-OTTER, we show that independently learned nuclear and electronic models remain predictive when composed end-to-end, reproducing experimental temperature- and pressure-dependent band-gap trends using models trained only on first-principles targets at zero pressure. By resolving the nonlinear evolution of Pb-s/Br-p antibonding at the valence-band maximum, it identifies the microscopic origin of the asymmetric pressure response. FLOW-OTTER thus establishes Hamiltonian learning as a general route from thermodynamic trajectories to experimentally grounded optoelectronic mechanisms.
ER -