Static spin exchange-correlation kernel of the uniform electron gas at finite temperature
Abstract
We determine the temperature and momentum dependence of the static spin exchange--correlation kernel of the unpolarized three-dimensional uniform electron gas using variational diagrammatic Monte Carlo. The calculations cover metallic densities with Wigner--Seitz radii rs=1 − 4 and temperatures T/TF=1/16 − 8, where TF is the Fermi temperature. At low temperature, the calculated kernel approaches established ground-state parametrizations. Heating suppresses its Fermi-scale minimum and reduces its magnitude, while the relative momentum dependence evolves nonmonotonically through the warm-dense crossover. At the two highest temperatures studied, the spin kernel is nearly constant over q ≤ 2kF, where kF is the Fermi wave number. The charge kernel at rs=1 retains pronounced momentum dependence under the same conditions, making a local approximation to the XC kernel more accurate in the spin channel over this interval. The directly sampled uniform response determines the XC free-energy curvature with respect to spin polarization, independently of a fitted polarization dependence. This curvature sets the interaction contribution to the free-energy cost of weak polarization and differs by several percent from the Groth--Dornheim--Bonitz parametrization at elevated temperatures. These results provide momentum-resolved reference data for finite-temperature spin-response theories and direct constraints on the spin dependence of thermal free-energy functionals.
Related
- The exact universal exchange-only local field factor of the uniform electron gas and its near-cancellation by parallel-spin correlation near 2kF
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- Adding Temperature to the Adiabatic Connection: Hybrid Functionals for Static and Dynamic Correlation
BibTeX
@misc{hou2026static,
title = {{Static spin exchange-correlation kernel of the uniform electron gas at finite temperature}},
author = {Pengcheng Hou and Zhiyi Li and Youjin Deng and Kun Chen},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2605.16888},
eprint = {2605.16888},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.16888},
}
RIS
TY - UNPB
TI - Static spin exchange-correlation kernel of the uniform electron gas at finite temperature
AU - Pengcheng Hou
AU - Zhiyi Li
AU - Youjin Deng
AU - Kun Chen
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2605.16888
UR - https://arxiv.org/abs/2605.16888
AB - We determine the temperature and momentum dependence of the static spin exchange--correlation kernel of the unpolarized three-dimensional uniform electron gas using variational diagrammatic Monte Carlo. The calculations cover metallic densities with Wigner--Seitz radii r_s=1 − 4 and temperatures T/T_F=1/16 − 8, where T_F is the Fermi temperature. At low temperature, the calculated kernel approaches established ground-state parametrizations. Heating suppresses its Fermi-scale minimum and reduces its magnitude, while the relative momentum dependence evolves nonmonotonically through the warm-dense crossover. At the two highest temperatures studied, the spin kernel is nearly constant over q ≤ 2k_F, where k_F is the Fermi wave number. The charge kernel at r_s=1 retains pronounced momentum dependence under the same conditions, making a local approximation to the XC kernel more accurate in the spin channel over this interval. The directly sampled uniform response determines the XC free-energy curvature with respect to spin polarization, independently of a fitted polarization dependence. This curvature sets the interaction contribution to the free-energy cost of weak polarization and differs by several percent from the Groth--Dornheim--Bonitz parametrization at elevated temperatures. These results provide momentum-resolved reference data for finite-temperature spin-response theories and direct constraints on the spin dependence of thermal free-energy functionals.
ER -