New answers tagged

1

ALGO only refers to the method used to reach convergence, as a result there is no difference in accuracy. ALGO = Normal / Fast tends to be faster than ALGO = All, however this can be system / level of theory dependent. It should be noted, this isn't strictly true since you can optimize to a different ground state minimum. This can result in a different ...


1

If the stress tensor is calculated by setting ISIF appropriately, then you can read the stress from the OUTCAR. There is no way to apply an axial stress from tags, however you can do a geometry optimization to 0 stress, then manually stress the cell in the Z direction by modifying the cell. You will need to do this for multiple volumes then fit a ...


13

It would probably be easier to use some software such as WinSCP. It allows you to select the location on your remote system and synchronise with the local system by matching either the time stamp or size (and probably other properties). Also if you are using Linux, read the answers on this Stack Overflow question to get an idea of alternatives. This way you ...


4

A lot of it will be in the difference in cost. But as a rule of thumb, GW potentials are typically harder, and include more states (semicores). This need not always be the case, since if you look at the Ag POTCARS, there isn't any difference at all in the recommended ENMIN/ENMAX, partial core radius, or even the states that are considered valence. In ...


12

I prefer to just download the data from the remote disks and then do the plots on my own local machine, which has all of my favorite tools for post-processing my data. I understand that this can be inconvenient though. It is indeed possible to run a GUI on a remote supercomputer though, if you first use ssh -X or ssh -Y when signing into the remote machine (...


2

Without any testing, I think the value of SYMPREC is also used for the tolerance $\delta$ in your expression. The subroutine related to the magnetic sites is called MAGSYM that can be found in symlib.F. In the subroutine, the magnetic moment of sites are compared with that of their corresponding sites after symmetry operation and the tolerance is set to a ...


5

NELECT tag should do the trick. A number that's larger than the default value (which is automatically calculated by VASP to be the number of valence electrons in the system) gives you charge doping and a real number that's lower than the default value gives you hole doping. Note that one doesn't necessarily needs to do a normal calculation to know the ...


3

Just putting another software that can be used to develop all the input files such as INCAR, POSCAR, KPOINTS and POTCAR from a CIF file, is pymatgen. https://pymatgen.org/. It is a python based software toolkit that can help you not only with the input files but also analyzing the output files from vasp. This software is being used in the development of the ...


6

To make Andrew Rosen's comment a full answer, you can use ASE to do this. ASE will still let you do some stupid things if you ask it to, but it can make selecting paw potentials easier (setup="materialsproject" for example will select potentials according to materials project, assuming you have the correct potentials available). It also helps ...


12

Let's just remind ourselves what k point sampling is. It is used to approximate the integral of a function over the Brillouin zone by replacing the integral with a sum over a finite number of points: $$ \int_{BZ} F({\bf k})d{\bf k} \approx \sum_j w_j F({\bf k_j}) $$ Now this is an approximation, and for any relatively sane function the error in this ...


4

As the error indicate: | Your generating k-point grid is not commensurate to the symmetry | | of the lattice. This can cause slow convergence with respect | | to k-points for HF type calculations | | suggested SOLUTIONS: | | ) if not already the case, use automatic k-point generation | | ) shift your grid to Gamma (G) (e.g. required for hex or fcc lattice) | ...


6

There is a discussion on this limitation on VASP page. Maybe the approach of a frozen f valence PAW pseudopotential could help you. Although magnetic properties might not be as well represented. I'm quantum espresso user and when their PAW potentials show problems (not so rare) I go to a norm-conserving solution like pseudodojo library, if you can do this in ...


5

Ionization energy is more appropriate for isolated atoms, you want the workfunction or ionization potential of your alloy surface. You calculate this usually from slab calculations because there is explicit vacuum. Work function is defined as: $$\Phi=E(vacuum)-E(Fermi)$$ If you use vasp this can be useful https://github.com/WMD-group/workfunction And a very ...


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