First-Principles Identification of Higher-Order Configurational Energy Terms and Their Magnetic-State Dependence in Lithium-Rich Oxyfluorides: From QUBO to HUBO
Abstract
In this work, we use spin-polarized density functional theory (DFT) to identify substantial third-order, nonadditive configurational energy contributions in lithium-rich oxyfluorides that quadratic unconstrained binary optimization (QUBO) models cannot represent. We test the extension from QUBO to higher-order unconstrained binary optimization (HUBO) in two disordered-rocksalt cathode materials, Li2MnO2F (LMOF) and Li2Mn0.5Ti0.5O2F (LMTiOF), using composition-preserving DFT energy maps. Using fixed-geometry energy maps, we show that cubic HUBO captures nonadditive contributions absent from QUBO models and substantially reduces fitting errors in both materials. Direct DFT energy differences confirm third-order nonadditivity, while comparisons of magnetic initializations reveal a strong dependence of the LMTiOF contribution on the converged electronic state. These results support the inclusion of higher-order terms when modeling configurational energetics and highlight the need to account for magnetic-state dependence in constructing DFT energy maps. The extracted terms describe effective couplings among composition-preserving exchange variables, rather than uniquely identified microscopic three-atom interactions.
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BibTeX
@misc{bae2026firstprinciples,
title = {{First-Principles Identification of Higher-Order Configurational Energy Terms and Their Magnetic-State Dependence in Lithium-Rich Oxyfluorides: From QUBO to HUBO}},
author = {Joonho Bae},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.38321},
eprint = {2610.38321},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.38321},
}
RIS
TY - UNPB
TI - First-Principles Identification of Higher-Order Configurational Energy Terms and Their Magnetic-State Dependence in Lithium-Rich Oxyfluorides: From QUBO to HUBO
AU - Joonho Bae
PY - 2026
DA - 2026/10/28
PB - arXiv
DO - 10.48550/arxiv.2610.38321
UR - https://arxiv.org/abs/2610.38321
AB - In this work, we use spin-polarized density functional theory (DFT) to identify substantial third-order, nonadditive configurational energy contributions in lithium-rich oxyfluorides that quadratic unconstrained binary optimization (QUBO) models cannot represent. We test the extension from QUBO to higher-order unconstrained binary optimization (HUBO) in two disordered-rocksalt cathode materials, Li_2MnO_2F (LMOF) and Li_2Mn_0.5Ti_0.5O_2F (LMTiOF), using composition-preserving DFT energy maps. Using fixed-geometry energy maps, we show that cubic HUBO captures nonadditive contributions absent from QUBO models and substantially reduces fitting errors in both materials. Direct DFT energy differences confirm third-order nonadditivity, while comparisons of magnetic initializations reveal a strong dependence of the LMTiOF contribution on the converged electronic state. These results support the inclusion of higher-order terms when modeling configurational energetics and highlight the need to account for magnetic-state dependence in constructing DFT energy maps. The extracted terms describe effective couplings among composition-preserving exchange variables, rather than uniquely identified microscopic three-atom interactions.
ER -