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Towards thermoelectricity with density-functional based tight-binding: Accuracy of phonon bandstructures
| Content Provider | Semantic Scholar |
|---|---|
| Author | Niehaus, Thomas A. Melissen, Sigismund Aradi, Bálint Allaei, S. Mehdi Vaez |
| Copyright Year | 2019 |
| Abstract | We calculate the phonon-dispersion relations of several two-dimensional materials and diamond using the density-functional based tight-binding approach (DFTB). Our goal is to verify if this numerically efficient method provides sufficiently accurate phonon frequencies and group velocities to compute reliable thermoelectric properties. To this end, the results are compared to available DFT results and experimental data. To quantify the accuracy for a given band, a descriptor is introduced that summarizes contributions to the lattice conductivity that are available already in the harmonic approximation. We find that the DFTB predictions depend strongly on the employed repulsive pair-potentials, which are an important prerequisite of this method. For carbon-based materials, accurate pair-potentials are identified and lead to errors of the descriptor that are of the same order as differences between different local and semi-local DFT approaches. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://export.arxiv.org/pdf/1904.06906 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
