UT theoretical chemistry code forum

If you can make a problematic AECCAR0 and AECCAR2 and the CHGCAR available, I can take a look at it.

My biggest concern is that you have relaxed the endpoints with ISIF=3 and the band with ISIF=2; the band has different lattice constants from the endpoints. Make sure you use the same settings and ideally the same code (they are with different versions of vasp) for the end point relaxation and the N...

I can not see the final geometries in your calculation, but I can see from your plot that this calculation is not converged and basically the calculation has gone bad. Try an initial run with TIMESTEP=0.01 until the forces drop below 1 eV/Ang. Check that things are reasonable and then continue with ...

It's pretty common to have high initial forces which can lead to unstable optimization. I recommend using a conservative optimizer in this case, such as IBRION=3 POTIM=0.01. You will likely just need about 10-20 iterations for the forces to drop to about 1 eV/Ang. Then you can go back to whatever op...

I am not an expert on this. Of course you can just post the xyz or XDATCAR file for others to view, but if you want an actual movie, maybe try jmol, vmd, or vesta. My students will know better than I will about how to make fancy movies.

The use of high temperature is just a trick to find possible diffusion mechanisms. If your material is active at 650 K on a time scale of seconds, that would imply a diffusion barrier of around 1.5 eV. But of course, you can only simulate maybe 10 ps, so if you want to see that same 1.5 eV barrier, ...

Just keep it simple. Relax the molecule above the surface for the initial state and then the dissociated fragments on the surface for the final state. Then connect them with a band, check to make sure that it looks reasonable, and then run the NEB.

This is a good question. In principle there are many possible product states from a given initial state. Typically, what you would do to study a reaction like to describe is to start by optimizing the CH3COOCH3 molecule above the surface. That optimized structure can be your initial state. Then you ...

We do do have a way to do that.

The SSNEB is implemented in our vtstcode, which can be linked into your vasp binary. If a change in the cell along a path is detected, it will be used by default.

Goodness, normally I can find simple problems with simple solutions. In this case, your initial and starting points looks reasonable, the band converged nicely, but the energy barrier is just very high. Unfortunately, I don't have a simple solution for you. One thing I would check is just to converg...

The charge is in units of e and the volume is in units of Ang^3.

In terms of meaning, the charge gives you a measure of the number of electrons associated with eon atomic center. The charge is integrated in the Bader volume around each atom.

Yes, I think that all of your statements are correct. For a path with intermediate minimum, it is best to minimize a nearby image to get an accurate energy of the intermediate minimum. You can also then run an NEB between the intermediate minimum and a final state to find the energy of a lower energ...

You can just use nebmake.pl for the initial path and then use the SSNEB to converge the path.

It is certainly true that a process with a 4 eV barrier will not occur at room temperature. If you want to upload the calculation, I can take a look at it. There are lots of ways to mess up a calculation and get an unphysical result.