AI Article Synopsis

  • Finite-temperature calculations are important for understanding material properties, but they are often costly and time-consuming due to the large sizes of systems needed for simulations.
  • This study proposes a new tight-binding model for efficiently and accurately calculating temperature-dependent properties in semiconductors, utilizing advanced modeling techniques that limit the number of parameters.
  • The model was tested on gallium arsenide, revealing that considering thermal expansion effects is crucial for accurately capturing electronic properties at high temperatures compared to experimental results.*

Article Abstract

Finite-temperature calculations are relevant for rationalizing material properties, yet they are computationally expensive because large system sizes or long simulation times are typically required. Circumventing the need for performing many explicit first-principles calculations, tight-binding and machine-learning models for the electronic structure emerged as promising alternatives, but transferability of such methods to elevated temperatures in a data-efficient way remains a great challenge. In this work, we suggest a tight-binding model for efficient and accurate calculations of temperature-dependent properties of semiconductors. Our approach utilizes physics-informed modeling of the electronic structure in the form of hybrid-orbital basis functions and numerically integrating atomic orbitals for the distance dependence of matrix elements. We show that these design choices lead to a tight-binding model with a minimal amount of parameters that are straightforwardly optimized using density functional theory or alternative electronic-structure methods. The temperature transferability of our model is tested by applying it to existing molecular-dynamics trajectories without explicitly fitting temperature-dependent data and comparison with density functional theory. We utilize it together with machine-learning molecular dynamics and hybrid density functional theory for the prototypical semiconductor gallium arsenide. We find that including the effects of thermal expansion on the onsite terms of the tight-binding model is important in order to accurately describe electronic properties at elevated temperatures in comparison with experiment.

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http://dx.doi.org/10.1063/5.0197986DOI Listing

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