Real-Time CASSCF Ehrenfest (TD-CASSCF) Modeling of Spintronics in a Tetrathiafulvalene-Based Nitronyl Nitroxide (BTBN) Model: The Competition between Charge Transfer and Spin Permutation.
- 1Departament de Ciència de Materials i Química Física & IQTCUB, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1, BarcelonaE-08820, Spain.
- 2Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, 80 Wood Lane, W12 0BZLondon, United Kingdom.
Abstract
Using real-time all-electron TD-CASSCF/Ehrenfest simulations, we investigate the molecular origin of magnetoresistance in the organic material BTBN, a tetrathiafulvalene-nitronyl nitroxide diradical. The calculations reveal that charge transport and spin dynamics are strongly coupled. In the high-spin state, where localized spins are aligned in parallel, charge propagates efficiently through the π-stacked system via coherent wave-like migration. In contrast, in low-spin states containing antiparallel spin alignments, the charge migration competes with the spin-permutation processes between localized radical spins. These additional spin-exchange pathways do not transfer charge but divert population away from the charge transport channel, reducing charge-transfer efficiency by roughly 50%, in the example studied, relative to the high-spin state. The simulations therefore identify the competition between electron migration and spin permutation as the fundamental molecular mechanism responsible for magnetoresistance in BTBN, explaining why magnetic-field-induced spin alignment enhances charge transport and lowers electrical resistance.
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BibTeX
@article{deumal2026realtime,
title = {{Real-Time CASSCF Ehrenfest (TD-CASSCF) Modeling of Spintronics in a Tetrathiafulvalene-Based Nitronyl Nitroxide (BTBN) Model: The Competition between Charge Transfer and Spin Permutation.}},
author = {Mercè Deumal and Jordi Ribas-Ariño and Michael A Robb},
journal = {The journal of physical chemistry letters},
year = {2026},
month = sep,
doi = {10.1021/acs.jpclett.6c02508},
url = {https://europepmc.org/article/MED/42915469},
note = {CC BY},
}
RIS
TY - JOUR
TI - Real-Time CASSCF Ehrenfest (TD-CASSCF) Modeling of Spintronics in a Tetrathiafulvalene-Based Nitronyl Nitroxide (BTBN) Model: The Competition between Charge Transfer and Spin Permutation.
AU - Mercè Deumal
AU - Jordi Ribas-Ariño
AU - Michael A Robb
PY - 2026
DA - 2026/09/01
JO - The journal of physical chemistry letters
DO - 10.1021/acs.jpclett.6c02508
UR - https://europepmc.org/article/MED/42915469
AB - Using real-time all-electron TD-CASSCF/Ehrenfest simulations, we investigate the molecular origin of magnetoresistance in the organic material BTBN, a tetrathiafulvalene-nitronyl nitroxide diradical. The calculations reveal that charge transport and spin dynamics are strongly coupled. In the high-spin state, where localized spins are aligned in parallel, charge propagates efficiently through the π-stacked system via coherent wave-like migration. In contrast, in low-spin states containing antiparallel spin alignments, the charge migration competes with the spin-permutation processes between localized radical spins. These additional spin-exchange pathways do not transfer charge but divert population away from the charge transport channel, reducing charge-transfer efficiency by roughly 50%, in the example studied, relative to the high-spin state. The simulations therefore identify the competition between electron migration and spin permutation as the fundamental molecular mechanism responsible for magnetoresistance in BTBN, explaining why magnetic-field-induced spin alignment enhances charge transport and lowers electrical resistance.
SN - 1948-7185
ER -