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Quantum Espresso: Studying topological insulators |
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Last update: 2023-10-28 |
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A benchmark density functional theory (DFT) calculation with Quantu |
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Espresso has been carried out on NEC SX-Aurora TSUBASA vector compu |
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to obtain the electronic properties of bismuth selenide (Bi2Se3) |
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topological insulator. |
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3D Dirac cone of Bi2Se3 (PDF, 1.2 MB) |
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The raw data (.txt) for reproducing the 3-D linear dispersion relat |
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plot can be downloaded below: |
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Bi2Se3 Dirac cone - upper band (TXT, 32 KB) |
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Bi2Se3 Dirac cone - lower band (TXT, 32 KB) |
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Calculation details: |
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+ Bi2Se3(111) slab model contained 6 quintuple layers (QL), |
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i.e. 30 atomic monolayers, |
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+ Non-collinear calculation with spin-orbit coupling included, |
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+ Grid of 3721 k-points within the first Brillouin zone, |
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+ Ultra-soft pseudopotentials and local density approximation for t |
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exchange-correlation functional (LDA), |
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+ Wavefunction and density cut-offs set to 15 and 150 Ry, |
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respectively. NOTE: This is a test run. Production calculations |
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would require much larger values and proper convergence tests! |
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+ Total energy convergence threshold: 1.0d-6 eV. |
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Quantum Espresso (version 6.3) has been compiled (vectorised) with |
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compilers (version 3.0.7) and run on 8 vector engines with MPI. |
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The QE code supporting SX-Aurora TSUBASA architecture: |
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https://github.com/SX-Aurora/QuantumEspresso |
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Performance notes by NEC. |
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https://www.nec.com/en/global/solutions/hpc/articles/tech23.html |
