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arXiv · 2605.01781

A Fully Ab-Initio Spin-Lattice Dynamics Framework for Magnetic Materials

Xianxi Zhang·Hongyu Yu·Liangliang Hong·Hongjun Xiang
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Abstract

Coupled spin-lattice dynamics (SLD) underlie a wide range of magnetic phenomena, yet a unified first-principles framework that propagates both degrees of freedom without empirical parameterization has remained elusive. We present a fully ab initio SLD approach integrated into VASP, in which interatomic forces and effective magnetic fields are obtained at each time step from self-consistent constrained-moment density-functional calculations. The method is validated on four materials spanning ferromagnetic, non-collinear, and geometrically frustrated orders, recovering the correct magnetic ground state in every case from random initial conditions. SLD trajectories also provide physically correlated training data for magnetic machine-learning potentials, as demonstrated for BiFeO$_3$ by a reduction of up to approximately one order of magnitude in energy MAE over training on randomized spin configurations. This framework opens a practical first-principles route to finite-temperature spin-lattice coupled phenomena in magnetic materials.

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Xianxi Zhang, Hongyu Yu, Liangliang Hong, Hongjun Xiang. 2026-05-03. A Fully Ab-Initio Spin-Lattice Dynamics Framework for Magnetic Materials. https://arxiv.org/abs/2605.01781

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