Difference between revisions of "Silicon Slab Structural Relaxation"
From William Parker Wiki
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* Create slab using copies of bulk structure coordinates | * Create slab using copies of bulk structure coordinates | ||
* Relax slab using loose total force convergence (~10<sup>-3</sup> Ry bohr) | * Relax slab using loose total force convergence (~10<sup>-3</sup> Ry bohr) | ||
| − | * Vary celldm(1) by fixed perentage around loosely relaxed slab and relax each new structure to tighter total force convergence (~10<sup>-4</sup>) | + | * Vary celldm(1) by fixed perentage around loosely relaxed slab and relax each new structure to tighter total force convergence (~10<sup>-4</sup> Ry bohr) |
| − | * Relax the minimum-energy structure from that | + | * Relax the minimum-energy structure from that step to the tightest force convergence (~10<sup>-5</sup> Ry bohr) |
| + | * Vary celldm(3) around the relaxed minimum energy structure and relax the in-plane (x & y) coordinates only | ||
| + | * Fit the equation of state to these energies and volumes | ||
Revision as of 13:23, 27 September 2021
Contents
Diamond
Single Layer
PBEsol
Relaxation Quality Parameters
| Step | Displacement q (b1, b2, b3) | Build-in Factor | Total Energy (eV/atom) | Total Force (eV/Å/atom) | Cell Pressure (GPa) | Resulting Mean ω1 (cm-1) | Lowest ω (cm-1) |
|---|---|---|---|---|---|---|---|
| 0 | - | - | -90.40389544 | 6.90e-05 | 0.010 | -0.493665 | -63.177 |
| 1 | 9 (-0.526 0.254 0.000) | 1.0 | -90.33443035 | 4.50e-05 | 0.000 | -0.718166 | -59.031 |
| 2 | 3 (-0.001 -0.513 0.000) | 1.0 | -90.40389384 | 6.00e-05 | -0.000 | -0.597389 | -64.901 |
Pair Distribution Functions
aPBEsol = 5.495 Å ; rNN, bulk, PBEsol = 2.379 Å
| Step | |
|---|---|
| 0 | 
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| 1 | 
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| 2 | 
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| 3 | |
| 4 |
Phonon Bands and Density of States
| Step | Phonons |
|---|---|
| 0 | 
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| 1 | 
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| 2 | 
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Relaxation Procedure
- Create slab using copies of bulk structure coordinates
- Relax slab using loose total force convergence (~10-3 Ry bohr)
- Vary celldm(1) by fixed perentage around loosely relaxed slab and relax each new structure to tighter total force convergence (~10-4 Ry bohr)
- Relax the minimum-energy structure from that step to the tightest force convergence (~10-5 Ry bohr)
- Vary celldm(3) around the relaxed minimum energy structure and relax the in-plane (x & y) coordinates only
- Fit the equation of state to these energies and volumes
