2
$\begingroup$

Can someone direct me on how to model a mesoporous material using VASP? I have the initial structure that I generated with a LAMMPS code which has two surfaces on the top and bottom of the slab (basically I introduced a vacuum gap on either side).

I need to convert this into a POSCAR and relax but I am having issues in understanding how to define the vacuum gap there.

Any help is appreciated. Thanks.

$\endgroup$
10
  • $\begingroup$ I gave my +1 long ago, but can you update us now that it has been 6+ months since you asked this question? Have you found the answer? Are you still actively in need of an answer? $\endgroup$ Nov 5, 2023 at 14:35
  • $\begingroup$ i still don't know, so i still need help if possible? $\endgroup$
    – Xdrake
    Nov 6, 2023 at 21:58
  • $\begingroup$ @Xdrake if you already have your POSCAR file ready, you have so many ways to add vacuum into the slab, one easy and automated way is to use vaspkit (a tool for pre and post processing VASP input and output files), you can access that option within the tool in the section of (Structural-Model options 801). On the other hand if you are still not able to get the POSCAR from LAMMPS code format then you can use cfg file format to dump the frames from LAMMPS, which will write the atom types and that can be read and converted into POSCAR through OVITO scripting interface. Hope this would help! $\endgroup$ Nov 7, 2023 at 9:10
  • $\begingroup$ Did the comment by Jaafar help answer your question? $\endgroup$ Dec 1, 2023 at 17:33
  • $\begingroup$ yes! Thank you, Jaafar. I'll give this some effort. $\endgroup$
    – Xdrake
    Dec 2, 2023 at 18:02

1 Answer 1

3
$\begingroup$

First we can start by converting the struture generated with LAMMPS into POSCAR file format

In this case, you can use cfg file format to dump the frames from LAMMPS, which will write the atom types, then you can read this file with OVITO, using the scirpting interface of OVITO https://www.ovito.org, you can convert this file into POSCAR format.

Now suppose that you have successfully produced the reqiured POSCAR format, adding vacuum or manipulating the position of the atmos(layers) is straightforwad. To do that you can use vapskit https://vaspkit.com (a tool for pre and post processing VASP input and output files). from vaspkit interface, head to ( Advanced Structure Models (option: 08)), then choose (801 for Build Vacuum Slab in Specified Direction). Make sure your POSCAR file in the same directory where you are running vaspkit. Afterwards choose the direction in which you want to add the vacuum level and the amount in Angstrom.

If you would like to further move the layers along certain direction, there is another option in vaspkit specifically for 2D systems which is accessible via option (92 2D-Material kit).

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .