UT theoretical chemistry code forum

You should always use the force criteria (negative ediffg). If you have linked with our NEB code, you can see the magnitude of the forces by grepping the outcar for "FORCES:"

It would certainly be easy enough to add to the script, but you can also do this analytically. In our script, we calculate the width as: width = Sqrt( Sum_i (E_i-E_avg)^2 /N ) where E_i are the d-band energies and E_avg is the average d-band level. If you want width_fermi = Sqrt( Sum_i (E_i-E_f)^2 /...

Did you freeze the bottom layers of your surface? If not, the entire slab may be translating.

Also, you don't need high precision, and you should not use vasp's conjugate gradients for the NEB.

That would be great. As long as you keep the author list and the references that describe the algorithm (which are listed in the source), it can be incorporated into another code. It would also be nice if improvements to the algorithm could be updated in a derived code, but this is not a requirement...

Using a relaxed cell could cause the problems that you are seeing.

Try using a frozen cell (ISIF=0) and a force criteria (ediffg=-0.01). Note that you need the negative sign to make this a force criteria. The energy criteria that you are using is not appropriate.

Are these calculations all converged? This is best done by choosing a force criteria - e.g. ediffg=-0.01.

Is the box frozen, or allowed to relax?

If you are using our code, you can just read the force from the OUTCAR. This contains both the perpendicular (real) and parallel (spring) forces. By grepping for NEB, you can also see the components. By specifying the convergence criteria, (e.g. ediffg=-0.01) you will require that the sum of these f...

A student, Dan Sheppard is still working on this implementation. We'll post when this has been properly testing and is ready to go.

If the molecule is really adsorbed to the surface there should not be any negative modes. If it is weakly physisorbed, you can ignore the lowest 6 modes - 3 rotation and 3 translation. Make sure that the modes are converged with respect to the accuracy of the forces (ediff) and the displacement size...

I would suggest looking for convergence in these charges with respect to an increasing lattice. Also, why don't you use the Bader volumes? The Voronoi partitioning is simply geometric and does not take into account the relative sizes of atoms. It is only in our code as a sanity check. As far as how ...

Something has gone very wrong. The file should contain the charge density, which is a positive quantity. Your files seems to have negative values. That, or it is not being read properly. If you make the file available, we'll take a look at it.

Make sure that you download our entire package of scripts:
http://theory.cm.utexas.edu/vtsttools/scripts/
They work together.

Since you have done 5 displacements, your next DISPLACECAR should be: 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0....

That is not so large. You will probably find that you don't need to displace all of the metal atoms. You can displace the molecular degrees of freedom, and then add the nearby metal atoms to see if the modes change.

Yes, you can continue a partially finished run. Take a look at the bottom of this page: http://theory.cm.utexas.edu/vtsttools/dynmat/ Basically, you can zero the displacements that have been done, and run again, and then collect the results using dymmatrix.pl Another possibility is to run the displa...