Search found 611 matches

by mverstra
Tue Jun 26, 2018 10:18 am
Forum: Response calculations
Topic: ANADDB calculation of electron-phonon
Replies: 3
Views: 4131

Re: ANADDB calculation of electron-phonon

you are missing the iqpt for the DS 12 13 14 etc.. I think. Perhaps start with a "simple" anaddb run, without eph, to check if the DDB is actually complete. Get a BS and DOS. The elph module is more difficult about having exactly what it asks for in the DDB and GKK files.
by mverstra
Sat Jun 23, 2018 12:47 pm
Forum: Response calculations
Topic: ANADDB calculation of electron-phonon
Replies: 3
Views: 4131

Re: ANADDB calculation of electron-phonon

Hi, lots of things: you will want to adapt the q grid to the 2D hexagonal system. right now you left 2x2x2 (3D grid, and not a multiple of 3, so no K point in electrons or phonons). Then, anaddb expects files containing _exactly_ the qpoints on the irreducible grid it generates from ngqpt + shiftq=0...
by mverstra
Wed Jun 20, 2018 5:35 pm
Forum: Response calculations
Topic: Temperature dependent electronic structure
Replies: 7
Views: 7398

Re: Temperature dependent electronic structure

Hello, setting kptopt?2 3 fixes it. Actually, the full calculation of the EPC matrix elements requires that you choose a _unique_ set of k+q wavefunctions (kptopt 3) in the WFQ file. This is a bug in the tutorial - I'll get it corrected. The code refuses to use symmetry to complete the k+q, because ...
by mverstra
Sat Jun 16, 2018 3:01 pm
Forum: Response calculations
Topic: Temperature dependent electronic structure
Replies: 7
Views: 7398

Re: Temperature dependent electronic structure

Probably right that the problem is elsewhere. To be more precise about what I said, if you want to do a random qpt, you can, but you need to do an intermediate step to get the GS wave functions at all k+q points. This is also in one of the rf tutorials. IF, however, your ngqpt is a sub-set of the ng...
by mverstra
Sat Jun 16, 2018 10:04 am
Forum: Response calculations
Topic: Temperature dependent electronic structure
Replies: 7
Views: 7398

Re: Temperature dependent electronic structure

check if your qshift is 0 0 0 - it defaults to 0.5 0.5 0.5 (I am lobbying for it to change) which shifts your q grid to values with 1/8, which would not be on your grid.

In any event the 1/6 grid will not work - it is not a supergrid of 4x4x4
by mverstra
Tue Jun 12, 2018 1:44 pm
Forum: Response calculations
Topic: Electron-Phonon gkk ascii file [SOLVED]
Replies: 4
Views: 6744

Re: Electron-Phonon gkk ascii file [SOLVED]

Hi again,

everything is in atomic units, essentially Ha as the perturbations are wrt reduced coordinates, E fields, etc... The prefactors and conventions follow the formulae in Savrasov and Savrasov or Grimvall. My phd (http://hdl.handle.net/2078.1/5178) has an old set of equations, which is still basically valid.
by mverstra
Sun May 27, 2018 2:49 pm
Forum: Ground state
Topic: electron phonon coupling supercell
Replies: 3
Views: 2832

Re: electron phonon coupling supercell

Hello, interesting, but the qpath has nothing to do with it - it is just for representation of band structures and lambda(q). The total lambda should be the same. Have you checked 1) that the phonons are the same (folded) as in the unit cell 2) that your convergence is as good as in the primitive ce...
by mverstra
Sun May 20, 2018 10:09 pm
Forum: Response calculations
Topic: missing files
Replies: 1
Views: 2847

Re: missing files

Hi, in the latest abinit version, this tutorial is called tutorespfn/tdepes. Could you try it as well (recompiling the latest version)? It seems your job did not get through even the first dataset, and crashed somehow. Do other tutorials work? You can also run "make check" from the abinit ...
by mverstra
Fri May 18, 2018 4:45 pm
Forum: Response calculations
Topic: SCAILD Method [SOLVED]
Replies: 2
Views: 4769

Re: SCAILD Method [SOLVED]

I can confirm this - the proto-implementation of SCAILD was removed from abinit last year, and TDEP will be announced in the coming versions.
by mverstra
Fri May 18, 2018 4:38 pm
Forum: Response calculations
Topic: Electron-Phonon gkk ascii file [SOLVED]
Replies: 4
Views: 6744

Re: Electron-Phonon gkk ascii file [SOLVED]

Hello, the output can be found in src/98_main/mrggkk.F90 Broadly, there is the standard abinit header, then the ground state eigenvalues, then the "first order eigenvalues" which are a matrix since the H(1) perturbation can mix the ground state bands: do i1wf=1,n1wf ! for each 1wf file, ge...
by mverstra
Wed May 02, 2018 5:28 pm
Forum: Response calculations
Topic: Difference between Eliashberg functions
Replies: 1
Views: 3074

Re: Difference between Eliashberg functions

Hi Jonas, very interesting topic! For the Gaussian case, it can come from the pileup of the gaussian tails, which do not go strictly to 0 at 0 frequency, even if there are no low lying eigenvalues in the phonon spectrum Given you have checked for this (tetrahedron + QGRID) I suspect you are getting ...
by mverstra
Tue Mar 13, 2018 2:06 pm
Forum: Ground state
Topic: Atomic or metallic?
Replies: 3
Views: 2784

Re: Atomic or metallic?

PS: what is the problem, actually? Did your calculation converge? Did you obtain something unexpected for the atom? There are already tons of publications using abinit for Bi, but it is not clear from your initial email what the issue is.
by mverstra
Tue Mar 13, 2018 2:03 pm
Forum: Ground state
Topic: Atomic or metallic?
Replies: 3
Views: 2784

Re: Atomic or metallic?

Dear friend of abinit! Don't worry, we are here. There are several confusing terms (metal and ensemble DFT, at least) and we need to be clear about what you actually want to do: To get a real metal you need a system which is not finite (at least a wire, plane, 3D solid). Your atom will not be a real...
by mverstra
Tue Nov 28, 2017 11:10 am
Forum: Response calculations
Topic: DFPT + PAW LDA
Replies: 6
Views: 6169

Re: DFPT + PAW LDA

Hi again, Indeed, these were 2 different issues. I have pared down your input to the following, to run it quickly, but still get errors related to complex potentials (cplex=1), and the dimensionality of the vxc1 and kxc1. I have forwarded this to the corresponding developers. There is a bug, and it'...
by mverstra
Fri Nov 24, 2017 10:01 pm
Forum: Response calculations
Topic: DFPT + PAW LDA
Replies: 6
Views: 6169

Re: DFPT + PAW LDA

Hi - preliminary analysis : gga is not the problem, you are all LDA. In your case nkxc should be 1: it's the size of the xc kernel used in the DFPT. It seems to be complaining when calculating the ddE derivative. Note also that you have some NaN just above during the calculation, so something has go...
by mverstra
Fri Nov 24, 2017 10:05 am
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

Indeed this is an important issue we are working on. In 2D (or 1D) you have to impose the _rotational_ sum rule as well, and that gives the parabolic band. For the moment in abinit this is not done (there is a version but it has numerical issues converging). We have a beta version from Olle Hellman,...
by mverstra
Tue Nov 07, 2017 8:44 pm
Forum: Response calculations
Topic: Electron Linewidth (elphon)
Replies: 3
Views: 3470

Re: Electron Linewidth (elphon)

Tdpes does the second option you propose (which contains Fermi and Bose factors with T).
by mverstra
Tue Nov 07, 2017 9:29 am
Forum: Response calculations
Topic: Electron Linewidth (elphon)
Replies: 3
Views: 3470

Re: Electron Linewidth (elphon)

There is a different tool chain, through the EIG2D files and either abinit or a python post-processing script. Basically there are additional diagrams you have to take into account for the Allen Heine Cardona approach.

See https://www.abinit.org/sites/default/fi ... depes.html
by mverstra
Mon Nov 06, 2017 8:58 pm
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

telphint 0 should do it - the epc and DOS calculations are separate parts of the code, indeed (no need of the electron phonon coupling to calculate the phonon DOS). The gaussian smearing variable is printed even though it is not used... ugly, I agree. Anaddb should also print out a PHDOS file, with ...
by mverstra
Thu Nov 02, 2017 5:15 pm
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

Near gamma things are clear, and now so is your DOS:

the second column is actually 3.99551488E-142 = 0

everything is fine except the printing of that column, which can not handle exponents greater than E-99

The starting frequency is a fixed buffer for the Gaussian case.

ciao
by mverstra
Thu Nov 02, 2017 1:58 pm
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

with tetrahedron dos you still have DOS at negative frequencies? It would be best to print out all of the frequencies for points on the DOS grid, to understand what is going on. You may still have an instability elsewhere in the BZ, though it would be very slight (few cm-1).
by mverstra
Thu Nov 02, 2017 11:00 am
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

"Gaussian method with smearing" = prtdos 1. Set it to 2 for the tetrahedron, and yes, the tail of the DOS is probably negligible.
by mverstra
Thu Nov 02, 2017 9:47 am
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

Hi again, have you tried tetrahedron DOS? As before, if you use gaussians they have a tail and the DOS conservatively calculates these down to some offset below 0, even if there are no imaginary frequencies. This can be safely ignored Otherwise you can print out the values on the full grid to determ...
by mverstra
Fri Oct 27, 2017 12:39 pm
Forum: Response calculations
Topic: Phonon DOS problem [SOLVED]
Replies: 17
Views: 18643

Re: Phonon DOS problem [SOLVED]

Hi again, those ifcsph are already quite small (18 bohr). From the ngqpt you use you can tell the maximum range of your force constants (1./(smallest q * gprim)), start with that and decrease progressively. If nothing works you probably really need more q points, make a denser grid or use the double...
by mverstra
Fri Oct 27, 2017 12:33 pm
Forum: Response calculations
Topic: Thermal conductivity for cubic materials
Replies: 3
Views: 3339

Re: Thermal conductivity for cubic materials

Your DDB and/or GKK files are probably incomplete, as the code complains. Check you have set rfatpol to 1 natom, and that all files have been included. You probably left the defaults for the tutorials and tests, which is just for 1 atom.