Calculating Temperature-Dependent Electronic Structure of Semiconductors using a Dynamic Tight-Binding Model

For theoretical calculations of large-scale system sizes or longer time-scale phenomena the computational costs of typical density functional theory can present a steep barrier, which motivates the development of alternative approaches. Here, we propose an extension of the tight-binding (TB) formalism which allows for the efficient calculation of temperature-dependent properties of semiconductors with little computational effort. Our TB approach employs hybrid-orbital basis functions and distance-dependent matrix elements that are calculated by numerical integration of the respective orbitals. Our method is straightforward since the TB parameters are only optimized at 0 K, which still provides a transferable scheme for accurate calculations of the electronic structure of semiconductors at finite temperatures. Combining the dynamic TB method with molecular dynamics, we show that it can account for dynamic changes to the symmetry of the crystal that are due to, e.g., lattice distortions.