Publication date: Dec 09, 2022
This work presents an application of the strain-fluctuation method, exploiting the fluctuations of the strain from extensive first-principles molecular dynamics simulations in the isobaric-isothermal ensemble, to the study of the elastic tensors of superionic materials. As the superionic materials for solid-state electrolyte applications usually do not have well-defined ground-state configurations, it is challenging to apply the static methods to calculate the elastic tensors of these materials. Instead, the strain-fluctuation method captures the dynamical nature of the elastic response of these materials and is a promising approach to studying their elastic properties. In this work: a protocol is presented and documented to extract the elastic the elastic moduli and their statistical errors from the molecular dynamics trajectories (open-source code available at https://github.com/materzanini); results for two benchmark superionic materials (Li₁₀GeP₂S₁₂ and Li₁₀GeP₂O₁₂) are given; for these superionic materials, a comparison to static methods is also provided, showing that static methods overestimate the moduli with respect to the correct dynamical treatment by ~25-50%.
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|104.4 MiB||Input and output files for the NPT-MD runs; the outputs of these runs (cell trajectories) serve as inputs for the strain-fluctuation method to extract the elastic tensors and moduli from the dynamics (open-source code at https://github.com/materzanini).|
|710 Bytes||Detailed description of the contents of MD-SIMULATIONS.tar.gz.|
|3.1 MiB||Input and output files for the static calculations (energy-volume isotropic compressions and Murnaghan fits; stress-strain calculations).|
|1.7 KiB||Detailed description of the contents of STATIC-CALCULATIONS.tar.gz.|