ABINIT Discussion Forums

kptopt2 should be -1 as you are doing calculation on 1 segment.

Without testing it (and without coffee), I can't see anything else wrong (well... ngkpt 4 4 200 seems excessive and ecut seems low but it's your call).

Simon

You should increase your k-grid a lot. For a metal, you want an adequate description of the Fermi surface in your ground state calculation which implies a dense k-grid. Depending on your computational resources, you might want to go up to something around ngkpt 20 20 20 (even more if you can). This ...

Hi, Doing a successful wannier90 run is complex. You should try different initial projections in your wannier90 input, this should help reducing the total spread of WF. The spread is not an easy quantity to converge, the code gets 'stuck' in local minima all the time. Projections accelerate (a lot) ...

Hi,

You have 4 V atoms in total (after the geometry builder). You need to specify two 5x5 matrices for each atom : 2 (spin) x 5x5 x 4 (atoms) = 200. You can probably just repeat the same matrices you already have for the 3 other V atoms.

Simon

Hi, natsph and iatsph work just like ndtset and jdtset. natsph = the number of atom you want your decomposition in (default = natom) iatsph = the index of these atom (must be smaller or equal to natom; you have to specify natsph of these) (default= 1 to natom) In your case, you could do it in 1 data...

You need to run AbinitBandStructureMaker again with your dbs as input. It will generate a .agr file that you can read using xmgrace.

You have oxygen with norm-conversing psp (is that right?). You need a large cut-off (ecut) of the order of 50 Ha.

Simon

Indeed, you should use rprim similar to a FCC system:
0 b/2 c/2
a/2 0 c/2
a/2 b/2 0
Keep us posted if it doesn't work.

I think you have to change your last rprim to 0 6 10. It cuts your unit cell volume by half and should yield the same lattice.

Hi, You don't need two atoms to define a face-centered orthorhombic (FCO) structure. The variable rprim will define the system as FCO, not the number of atoms. In your case, I think you don't need the second atom. In the last case, it's clear why abinit failed : xcart = a 0 0 is equivalent to 0 0 0 ...

To get the Fermi surface in BXSF format (for XCrysDen), you can use the prtfsurf variable. However, you can only it with a non-shifted k-grid. The 3 different Fermi levels you get are probably due to different k-grid. You need a very dense k-grid in a metal because of the Fermi surface (this is more...

Hi,

Your ecut value is very low. Your calculations will probably not be accurate. If increasing ecut to a 'reasonable' value doesn't solve your problem, you can set nline to 8 (or higher if it doesn't work).

FYI, you can use chkprim 0 to bypass the symfind error.

Simon

Your ecut is quite low, especially if you're using norm-conversing pseudo. Are you sure you are converged?

Also, your k-grid seems small (it's hard to tell without rprim and acell). Increasing it might get rid of these imaginary frequencies.

Simon

Hi, I tried running your input with abinit 6.8.1 and it works, which is strange. Anyway, you replace acell, angdeg, spgroup and spgaxor with acell 1.2047004070E+01 1.2047004070E+01 1.2047004070E+01 Bohr rprim 4.7241905504E-01 0.0000000000E+00 8.8137406159E-01 -2.3620952752E-01 4.0912690290E-01 8.813...

Have you checked rprim? It's possible that acell is fixed but rprim changes.

Can you send your log so we can have a better idea what the problem is?

Simon

There seems to be something wrong with your pseudo-potential as zval is greater than 22 (the nuclear charge of Ti).

Can you post the full log (from ABINIT) so we can get a better idea what is going on?

Cheers,

Simon

Hi, I tried your input file with a homemade pseudopotential. It has 2 errors: rprim gives a negative volume a1 . (a2 x a3) so you should switch the first line with the third (in rprim) the k-point grid is not symmetric. Either set chksymbreak to 0 or use a Monkhorst-Pack sampling for FCC (recommende...

Hi,

v5/t38, t39 and t40 are test, not the DFT+U tutorial. In any case, what's the error you get? Can you post a log file so we can get a better idea what's going on?

Did you change the input?

Finally, what version of ABINIT are you using?

Simon

You want to have the right number of k-points in the wavefunction you're reading. This means that your ground state calculation should be done with the same kptopt as the phonon calculation.

Simon

Hi, You should first deal with the warning about the k-points. You didn't use the same kptopt in the GS calculation and in the phonon calculation. You should do your GS calculation again but with kptopt 2. Also, you didn't use the same tsmear in both calculations. I'm not sure if this will change si...

Hi, It's normal that grep DIS wannier90.wout returns nothing become no disentanglement is done in this tutorial. For the convergence though, your results are perplexing. I tried to run the tutorial and it worked great. The spread started at 52.46 like yours but quickly converged to 4 (or something l...

The loggrid is indeed quite large. I don't think it's necessary to keep it at that value. I just tried it with loggrid=2001 and it looks ok (from the logderivate and wfn point-of-view).

Simon

Hi maxim, I recently made a pseudo for Zr. Here's the input for atompaw: Zr 40 GGA-PBE loggrid 3001 5 5 4 0 0 0 4 2 2 5 0 2 5 1 0 0 0 0 c c c v v c c v v c v 2 3.2 y 5.0 n n y 2.0 n VANDERBILT 3 0 2.0 5.0 2.5 3.0 2.0 2.0 2.0 0 It has 12 electrons. It's probably not optimal but it worked great for th...

This is indeed large. To improve upon this, you could change your initial projections. I recommend using the sp3 on Si and the bonding orbitals. However, you shouldn't use r=4 for the sp3 orbitals as you are using a pseudopotential, not a full atomic wavefunction. r=1 (the default value) should be b...

Is your total spread well converged?
You can look at this by using:
grep CONV wannier90.wout
The total spread is the 4th column. If the convergence is poor (it happens often), you would need to increase the number of k-points in dataset 2 and 3.