Saved in:
Bibliographic Details
Main Authors: Yuan, Wei-Zhe, Guo, Yangyu, Yi, Hong-Liang
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.29437
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913169768710144
author Yuan, Wei-Zhe
Guo, Yangyu
Yi, Hong-Liang
author_facet Yuan, Wei-Zhe
Guo, Yangyu
Yi, Hong-Liang
contents Predictive modeling of the infrared dielectric function in polar materials is crucial for thermal management and infrared devices design. While the Green-Kubo molecular dynamics (MD) framework provides a nonperturbative route to compute dielectric responses from dipole fluctuations, yet it commonly relies on the fixed-charge approximation that neglects dynamic charge redistribution during atomic motion. Here, we employ a machine-learning neuroevolution potential with dynamic charges (qNEP) combined with Green-Kubo MD to investigate the dynamic charge effect on the infrared dielectric response of rutile TiO$_2$, a material with large Born effective charges (BEC). Our results show that dynamic charge effects become increasingly important at elevated temperatures and are essential for accurately predicting longitudinal optical phonon features and infrared reflectance. This work establishes that accurate prediction of infrared optical properties in polar materials under thermal excitation requires explicit treatment of dynamic charge evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2605_29437
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Dynamic charges effect on infrared dielectric response of polar materials
Yuan, Wei-Zhe
Guo, Yangyu
Yi, Hong-Liang
Materials Science
Predictive modeling of the infrared dielectric function in polar materials is crucial for thermal management and infrared devices design. While the Green-Kubo molecular dynamics (MD) framework provides a nonperturbative route to compute dielectric responses from dipole fluctuations, yet it commonly relies on the fixed-charge approximation that neglects dynamic charge redistribution during atomic motion. Here, we employ a machine-learning neuroevolution potential with dynamic charges (qNEP) combined with Green-Kubo MD to investigate the dynamic charge effect on the infrared dielectric response of rutile TiO$_2$, a material with large Born effective charges (BEC). Our results show that dynamic charge effects become increasingly important at elevated temperatures and are essential for accurately predicting longitudinal optical phonon features and infrared reflectance. This work establishes that accurate prediction of infrared optical properties in polar materials under thermal excitation requires explicit treatment of dynamic charge evolution.
title Dynamic charges effect on infrared dielectric response of polar materials
topic Materials Science
url https://arxiv.org/abs/2605.29437