Symmetry-based modal analysis of heat transport in molecular dynamics of quasi-1D systems
Abstract
Detailed analysis of thermal conductivity results obtained from molecular dynamics (MD) trajectories conventionally relies on knowledge of the harmonic vibrational modes of the system. This is the case in methods like Green-Kubo modal analysis (GKMA) and homogeneous nonequilibrium modal analysis (HNEMA). However, arbitrary mixing within degenerate phonon subspaces makes individual modal contributions basis dependent and can obscure their symmetry character. We propose an alternative for quasi-one-dimensional (quasi-1D) systems: we construct the modal basis for the decomposition of the thermal conductivity from line-group projection operators, so that every projected component carries well-defined symmetry labels (including rotational information and parities) and the decomposition is unique at the level of irreducible representations (irreps). Applying the idea to a (10, 0)-(20, 0) WS2-MoS2 double-walled nanotube (DWNT) described by a neuroevolution potential (NEP), we find that at 300 K both HNEMA and GKMA yield statistically consistent total conductivities and allow the identification of several prominent symmetry-adapted conduction channels. The GKMA pair matrix shows that within-block and same-channel cross-k terms account for 75.6% of the total conductivity, while cross-channel correlations contribute 24.4%.
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BibTeX
@misc{cen2026symmetrybased,
title = {{Symmetry-based modal analysis of heat transport in molecular dynamics of quasi-1D systems}},
author = {Yu-Jie Cen and Sandro Wieser and Georg K. H. Madsen and Jesús Carrete},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.02397},
eprint = {2609.02397},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.02397},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Symmetry-based modal analysis of heat transport in molecular dynamics of quasi-1D systems
AU - Yu-Jie Cen
AU - Sandro Wieser
AU - Georg K. H. Madsen
AU - Jesús Carrete
PY - 2026
DA - 2026/09/16
PB - arXiv
DO - 10.48550/arxiv.2609.02397
UR - https://arxiv.org/abs/2609.02397
AB - Detailed analysis of thermal conductivity results obtained from molecular dynamics (MD) trajectories conventionally relies on knowledge of the harmonic vibrational modes of the system. This is the case in methods like Green-Kubo modal analysis (GKMA) and homogeneous nonequilibrium modal analysis (HNEMA). However, arbitrary mixing within degenerate phonon subspaces makes individual modal contributions basis dependent and can obscure their symmetry character. We propose an alternative for quasi-one-dimensional (quasi-1D) systems: we construct the modal basis for the decomposition of the thermal conductivity from line-group projection operators, so that every projected component carries well-defined symmetry labels (including rotational information and parities) and the decomposition is unique at the level of irreducible representations (irreps). Applying the idea to a (10, 0)-(20, 0) WS2-MoS2 double-walled nanotube (DWNT) described by a neuroevolution potential (NEP), we find that at 300 K both HNEMA and GKMA yield statistically consistent total conductivities and allow the identification of several prominent symmetry-adapted conduction channels. The GKMA pair matrix shows that within-block and same-channel cross-k terms account for 75.6% of the total conductivity, while cross-channel correlations contribute 24.4%.
ER -