UT theoretical chemistry code forum

Thanks Graeme. I'll try those. I guess I should have known about the EDIFF issue.

Here is the DIMCAR from one of my runs:

Step Force Torque Energy Curvature Angle
1 6.74769 17.61536 -1002.94132 14.73217 44.27777
1 6.74769 7.41450 -1002.94132 3.57505 42.55853
1 6.74769 4.97267 -1002.94132 2.32063 33.29783
1 6.74769 6.96414 -1002.94132 3.73984 17.54976
2 6.54296 5.95716 ...

Thanks. I think I got something to work. I appreciate the help.

So, I started a couple of runs and got about 45 ionic iterations before running out of time. During the runs, atoms moved at most 0.3 angstroms. Forces are still pretty high. Starting with random displacements, how many ionic ...

Quick question: I set up the DISPLACECAR_sp file to have two moving atoms. In the dimer displacements it makes, it seems that only one is displaced at a time. Is that what is meant to happen, or have I messed something up?

Thanks for the advice Graeme. I may start with the simpler method you mentioned at the end, but if I find some time, I'll try out the akmc scripts.

I'm trying to find if an oxygen di-interstitial in UO2 can move in a concerted way. I already tested an initial guess with NEB and found it decomposed into two single hops. So, I'm wanting to do some dimer searches.

I don't want to bias the searches in terms of guess a saddle point, though I can ...

Well, these are the lines that used to be in there:

$c=2.99792458e10;
$prehertz=$prefactor*$c/10e12;
print " (in units of TerraHertz) is $prehertz\n";

Maybe one of you guys could fix it? It would take me longer to figure out how to use CVS again (I only use it once or twice a year...).

It is, you need to convert it to Hz for the standard usage of it. Do that by multiplying by the speed of light in cm/s and divide by 10e12. That should do it. (This gives the prefactor in units of TerraHertz.)

Graeme, my original script also gave the prefactor in Hz but the new one does not. Is ...

It's been a while, but it does look like the <displacement> argument isn't used. It must be that at one point I used it to calculate the actual force constants, rather than just the force difference, which is what it seems it is spitting out right now. So, I'm a little confused as to when it ...

Hi,

Just my two cents. The parallel version of the code was set up so you could get through all of the degrees of freedom you want to displace more quickly. It's true that you could do it all in multiple single processor runs, but the parallel version was meant to be a bit more convenient. You didn ...

Is there a script to convert xyz to poscar? I see other scripts involving xyz and vasp files, but not one for this (unless I missed it).

A bigger question: is there a simple script to convert output from the ICSD database into POSCAR? Anyone know? I can use CrystalMaker to get an xyz file (hence my ...

I added three scripts: avgCHGCAR.pl, avgPARCHG.pl and diffCHGCAR.pl, which either average or subtract CHGCAR/PARCHG files.

The two types of files are very similar (CHGCAR vs PARCHG) except in how many entries they have in each line for the charge density on each FFT grid point.

For them to work ...