Silicon's electronic band structure from first principles¶
System(s): Polaris · Code: Quantum ESPRESSO · Outcome: Success
The ask¶
(This campaign predates verbatim prompt logging — the request below is reconstructed from the campaign's documented design, not a direct quote.)
"Compute the electronic band structure and band gap of crystalline silicon using DFT."
What happened¶
Trinity ran the full four-step Quantum ESPRESSO band-structure workflow (self-consistent field → non-self-consistent field → band calculation → post-processing) on a 2-atom silicon unit cell. Early attempts failed because the required pseudopotential library isn't bundled with the installed version of Quantum ESPRESSO on this system — it had to be found and staged first, a fact now captured for future runs.
Results¶
- Computed an indirect band gap of 0.54 eV (DFT-PBE typically underestimates the experimental 1.17 eV band gap by roughly 50%, a well-known limitation of this method, not an error).
- Full 4-step workflow completed in about 24 seconds total on one GPU node — roughly 50x faster than the same calculation would take on CPU.
- Key infrastructure finding: this Quantum ESPRESSO installation ships no pseudopotential library by default; pseudopotentials must be pre-staged.