UT theoretical chemistry code forum

You can certainly have two steps in a single path. I typically discourage that for two reasons. First, if you have an intermediate minimum, you probably want to find that by minimization. Then, if you know the intermediate minimum, you can run the two NEB calculations at the same time and so there c...

Hi Emerick, I think the method is fine, but if your goal is to find the minimum energy pathway after you have a saddle (which it seems that you do) then there could be an easier way. What could be more efficient is to run 4 minimization calculations: 1. from your initial state to the minimum at 0.4 ...

I have to guess a little without seeing all the files, but I'm almost sure that I know what this issue is related to. The spline interpolation uses the force and energy for every pair of adjacent images along the path, as well as the distance between them. If there is a displacement along any soft m...

For cube files, the atomic volumes are in bohr^3.

It looks fine to me. The max force is down to 0.02 eV/Ang and the barrier is dropping slowly but steadily. Just continue the run. There will be faster optimizers, but start by getting it to converge with your current settings and then you can try second order optimizers if you want to increase effic...

Ok, great, and thanks for the feedback; I've added vtst-182 to a vtstcode6.2 directory.

that seems good to me

I think that you are right. That ZPE script just calculates quantum harmonic corrections to TST, so zero or negative modes will lead to a divergence. If you can identify 3 translational modes at both the reactant and saddle, as well as (perhaps) 3 rotational modes, you can simply remove them and run...

Don't use vtstcode6.4; use vtstcode6.1 (it is in our vtsttools download). That should work for vasp6.2, but if there are problems, I can send a specific version that will work.

Also, yes, here is v182:

Ah no use the code in vtstcode6.1. If you have any problems, please let me know. We have changed the vtstcode version system so that it just matches the version of vasp.

But also, maybe just download vasp6.4 so that you have the latest version.

v1.05 08/19/23

Proper reading of negative direct coordinates.

You can select degrees of freedom near the atoms that have moved in the reaction and look for convergence as you add more degrees of freedom. We have some scripts for this, such as dymseldisp.pl. Note that you can also combine dynamical matrix calculations with our code, and run any/all displacement...

It is not building the binary because it can't find the associated libraries at the linking stage. Try removing the -static from the makefile; the static libraries might not be installed.

It seems that we don't have a script for exactly this task. That said, it would be quite easy to modify one of our chg* scripts, which will allow you to read chgcar files, and then integrate over which ever dimensions that you want.

Make sure that you have copied the source code from your vtstcode/vtstcode6.3 directory into your vasp.6.3.2/src directory. Also do a "make clean". If these steps don't work, please let me know.