QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: gayani2025 on June 25, 2025, 10:05
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Dear All, I'm trying to do a geometry optimization of this perovskite. I found a similar relevant settings which describe there system
Previous study
The DFT calculations were performed using the Fireball package. All geometry optimizations and electronic structure analyses were performed using the BLYP exchange-correlation functional with D3 corrections and norm-conserving pseudopotentials with a basis set of optimized numerical atomic-like orbitals. Systems were allowed to relax until the remaining atomic forces reached below 5 × 10−2 eV Å−1. a 2 × 2 unit cell containing 300 atoms. The Brillouin reciprocal zone was sampled by a Monkhorst-Pack grid of 5 × 5 × 1 for the 2 × 2 slab.
Based on above details I have set up the system.
I am using GGA-BLYP functional and Grimme D3 dispersion corrections. A norm-conserving LCAO basis set (analogous to those in PseudoDojo) is used with a 600 eV density mesh cutoff. Occupations were modeled using Fermi–Dirac smearing at 300 K. Brillouin zone integration is performed with a 5×5×1 Monkhorst-Pack grid.
My question is I have selected Norm conserving Pseudo Dojo potential. Is it a good choice ? Do I have to switch to SG15 or FHI. This is a semiconducting material (so I selected Fermi Dirac smearing 300K) with a band gap of 1.5-1.9 eV. Please advice. Thanks
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PD-Medium will be more accurate, typically, than FHI and SG15.