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How to optimize the monolayer in VASP?
For the geometric optimization of the monolayer in VASP, you should use the following key tags: You can search the explanation for each tag in VASPWIKI. For completeness, I give an INCAR template for geometric optimization in VASP.
What’s the difference between isif 2 and isif 3?
ISIF=2 is the ions-only relaxation. I am using VASP 5.4.1. But speaking of an ions-only relaxation, I can actually use ISIF=2 to relax the ions with symmetry, and C2 remains throughout (down to EDIFFG = -1e-6). However, ISIF=3 is a different story, as I mentioned previously. sorry, they apparently changed the meaning of the tag between version.
Which is the best isif setting for geometry relaxation?
I personally prefer ISIF=2 so that the volume of the supercell will stay constant. This makes comparison with other systems easier since I am assured that they will have the same supercell shape and volume.
What should I set lwave to in VASP?
I recommend setting LWAVE =.TRUE. for most jobs, unless you are using an ASE-based optimizer or running many short jobs in succession. There is a large file I/O cost, but the WAVECAR serves as an excellent starting guess for continuation jobs, if needed, and can be deleted when you’re done.
What should encut be for geometry optimization in VASP?
Do an initial optimization with “looser” settings (e.g. gamma-point only for the k-point grid, 400 eV cutoff if relaxing the atomic positions) and then refine it with the desired parameters. When performing geometry optimizations that involve changes in the cell shape and/or volume, always ensure that ENCUT > 1.3* ENMAX to prevent Pulay stresses.
How to calculate aggac for n-layers in VASP?
AGGAC = 0.0000 For more strong interlayer interaction, you should use the scan+rvv10 method (VASP 5.4.4 or more recent version): In addition, if you POSCAR contains lots of atoms with n-layer structure, larger than 10, you should add: LREAL=auto. May it helps.
How to optimize bulk structure in VASP Stack Exchange?
You should also change your KPOINT file to k k 1; where k is equal to the number of points used to optimize your bulk structure and 1 is set in the direction of the vacuum. Automatic mesh 0 Gamma k k 1 0.