Data from: Ferroelectric fractals: Switching mechanism of wurtzite AlN
Data files
May 30, 2026 version files 432.41 MB
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MLFF-DRYAD.zip
432.40 MB
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README.md
4.08 KB
Abstract
Aluminum nitride (AlN) and other wurtzite materials are widely used in piezoelectric microelectromechanical systems and are of great interest for future thin-film ferroelectric devices. Much progress has been made by modeling these materials with quantum mechanical methods such as density functional theory (DFT). However, there are very few existing methods that can model AlN on a larger scale, and none that can model multiple phases and domain walls with the accuracy of DFT. In this work, we present a machine-learned molecular dynamics force field (MLFF) for AlN constructed by fitting an artificial neural network to an underlying DFT dataset. Using our trained MLFF, we can predict the energies, forces, and phonon dispersions of AlN with the accuracy of DFT at dramatically lower computational cost. Accordingly, our MLFF can simulate systems orders of magnitude larger than DFT, enabling the study of emergent and long-range effects, such as the frequency-dependent dielectric function and multiple ferroelectric domains. This method can easily be expanded to other wurtzite nitrides, oxides, and solid solutions.
Dataset DOI: https://doi.org/10.5061/dryad.3n5tb2rzr
Description of the data and file structure
This Dataset encompasses all the data required to reproduce the information presented in "Ferroelectric fractals: Switching mechanism of wurtzite AlN," published in Phys. Rev. Lett. (https://doi.org/10.1103/2qs8-yxmr) and the companion paper "Multidomain simulations of aluminum nitride with machine-learned force fields" published in Phys. Rev. B (https://doi.org/10.1103/PhysRevB.110.035204)
Overview
This dataset contains all data and simulation inputs required to reproduce the results presented in:
* Ferroelectric fractals: Switching mechanism of wurtzite AlN (Phys. Rev. Lett., https://doi.org/10.1103/2qs8-yxmr)
* Multidomain simulations of aluminum nitride with machine-learned force fields (Phys. Rev. B 110, 035204, https://doi.org/10.1103/PhysRevB.110.035204)
The archive MLFF-DRYAD.zip contains three top-level directories: MD, Monte Carlo, and MLFF.
Required software
The dataset was generated and analyzed using the following software:
* LAMMPS (molecular dynamics simulations)
* AENET (machine-learned force field training, http://ann.atomistic.net)
* OVITO (trajectory visualization)
* ALAMODE (phonon calculations)
* Python 3 (for post-processing scripts)
File: MLFF-DRYAD.tar
MD
This directory contains molecular dynamics simulation inputs, outputs, and analysis scripts used to compute domain wall motion and switching behavior.
* dw-velocity.csv: domain wall velocity data used in the manuscript
* generic/: input files required to run LAMMPS simulations
* analysis/: Python scripts used to identify and visualize up/down polarization domains from MD trajectories
Monte Carlo
This directory contains Monte Carlo simulation code, outputs, and plotting scripts.
* monte.py: runs Monte Carlo simulations and produces dumpovito.xyz
* plotflip.py and plotlogflip.py: generates plots from dumpovito.xyz
plotflip.py: raw KAI switching curve (sigmoid plot) and plotlogflip.py: Avrami plot (linearized KAI analysis).
MLFF
This directory contains the machine-learned force field (MLFF) for AlN and all training, validation, and analysis data generated using AENET.
* Al.nn, N.nn: trained neural network potential files for Al and N used in simulations
train/
Contains training data and configuration files for the MLFF.
* dataset/: DFT structures used for training
* Remaining files: AENET input and configuration files required for model training
* All other files are compatible with with the AENET code and are detailed in that documentation
dielec/
Contains scripts for computing dielectric properties from molecular dynamics trajectories.
* getpolar.py: converts MD trajectories into macroscopic dipole moment time series
* Additional scripts compute and plot dielectric response functions
evcurves/
Contains energy–volume curve calculations for multiple AlN phases.
* Each phase has its own directory
* energy.csv in each directory contains computed energy–volume data
* each file in that directory corresponds directly to either the Quantum Espresso or AENET codes used to run the calculations as detailed in the documentation for that code
phonons/
Contains phonon calculations for wurtzite AlN using both DFT and MLFF methods.
* Each subdirectory follows the ALAMODE workflow (https://alamode.readthedocs.io/en/latest/index.html)
QE-MD-compare/
Contains comparison data between DFT molecular dynamics and MLFF simulations.
* compare.csv: summarized comparison data used in the manuscript
* Includes all input and output files required for reproduction
