ABINIT Discussion Forums

Hi, the following may be a bug, I've uncovered it as I work on the ffield tutorial. In a DFPT run, in order obtain the clamped and relaxed piezoelectric constants, it works if the phonons, strains, and electric fields are computed in a single dataset. However, it fails if the electric field perturba...

Thanks Matteo that work-around seems to be fine.

Joe

Hi, I can compile abinit 9.0.0 with gcc in debug mode "enhanced", but not with intel 19, because of the ABI_UNUSED macro. I believe the problem is that m_xmpi.F90 uses this macro, and is compiled under directory "12_hide_mpi", but the routine "unused_var" that the macro calls is not defined until di...

Even re-doing a GS calc after relaxation and then a response function calc, fails. That is: ndtset 4 1) Relax ions 2) Relax ions and cell using ions from 1 3) Compute accurate GS WFK and DEN, using cell and ions from 2 4) Compute DDK using WFK, cell, and ions from 3 == FAIL The output file reports c...

Hi,
I need more information to give a helpful answer. In particular, how many kpts are you using? How many nodes? PAW or NCPP?

thanks,
Joe

If you do an SCF calculation with nstep 1, nline 0, the output will be just the result of the input density.

If you have a DEN file created from a previous Abinit run, you can use irdden 1 to read it at the start of a new calculation. getden only works in multi-dataset mode.

So you're saying you have partial occupancy of sites (chemical disorder). Generally this is handled by creating a supercell, with the equivalent site occupied by different atom types in different cells. In abinit, and other DFT codes, a site can be occupied by one and only one atom at a time.

Hi, I notice that in getghc, m_hamiltonian, etc there is now code for application of H between different K points (K_H_K, KPRIME_H_K, etc). I'm not quite clear how and where this is being used in the code. Is it part of Hartree-Fock (the Fock operator)? Is it coded also for PAW? (doesn't seem to be)...

Hi everyone, I'm back to development. Currently I'm putting the finishing touches on implementing nuclear magnetic dipoles--they are input with nucdipmom(3,natom) input variable, and then the Hamiltonian is modified to include them (in PAW, both on-site terms and the bare A.p term). Two questions ar...

The richest source for XC's in abinit is libxc, which can be compiled in when abinit is built. You need to see if the xc you want exists (yet) in libxc, compile in the proper version to abinit, and also build your pseudopotentials or PAW data sets with libxc and the xc functional you want.

yes in the v1 folder of the tests, see tests 78 and 80

Although your system contains a metal atom as an impurity, that doesn't necessarily make it have bulk metallic behavior (imagine a 1 gram sample of Si with a single Pd atom in it--still looks pretty much like Si). All diemac does is help with scf convergence. It's unlikely that the optimum value in ...

Hi, yes, I think in anaddb the elastic tensors could be symmetrized pretty easily, that would clean the output (but it would still "look" non-standard if the cell was not aligned in a nice way). As for cell alignment, there are (I think) just the 14 crystal classes to consider. I've been b...

OK, after much work, I think I understand what abinit is doing. a) there is no symmetry breaking in the strain code. The elastic tensor that comes out is symmetry-correct (I checked this carefully by writing python code that did a full symmetry projection of the elastic tensor using all the space gr...

fcc copper has a lattice constant of about 3.61 angstrom, your value corresponds to about twice that. It almost looks like you got the lattice constant from somewhere in Bohr, but thought it was in angstrom and then converted the number to Bohr. Short answer is that your acell is much larger than th...

As far as I know, Abinit doesn't have a check point facility to restart a job in the middle of an scf cycle. You have a lot of atoms in your unit cell. How many cores are you running on? You need to be running in parallel over bands and FFT planes ( you have a small number of k points so the default...

I think your question is posted in the wrong part of the forum, this section is for response functions (phonons, electric field, etc). Your question is more of a ground state question.

In any case, what are you using for kptrlatt, and shiftk?

Hi, can someone shed light on the use symmetry in the rfstrs (strain) DFPT calculation? My example is aluminum--an FCC cell, only 1 atom in the primitive cell. Questions arising: 1) The code with rfstrs 3 runs all 6 strain calculations, though by symmetry for this crystal I would think fewer would b...

Hi, I'm running electric field perturbation calculations of the type I've done many times before--general chain of calculations looks like 1) GS, saving WFK 2) DDK, rfdir 1 1 1, reading WFK from 1), saving 1WF.. 3) rfelfd 3, rfdir 1 1 1, reading WFK from 1) and 1WF from 2 Usually this works but now ...

Hi, I must be missing something obvious here--I am trying to reproduce data in Gillet, Giantomassi, and Gonze, CPC 203, 83 (2016). Doing a BSE calc with an 8x8x8 k pt mesh works and give an answer similar to the cited paper; doing 4x4x4 with bs_interp_mode 1, bs_interp_method 0, bs_interp_kmult 1 1 ...

Hi, just wondering where the feature set for BSE calculations stands in 8.2 (which I guess should be released shortly?) and beyond. Specifically:

1) Support for NCPP's with multiple projectors (for example Hamann oncvpsp type)

2) Interpolation with PAW

3) Interpolation with parallelism

thanks,
Joe

Hi all (long time no see!) can someone provide a rough estimate for the memory needed per processor during the screening calculation and the BSE calculation? For example, running nbands with nkpts on nprocs, how much memory/processor should be available? These calculations seem to be running well ex...

you will have to model the disorder somehow, either with supercells or special quasirandom structures. This in itself is complex and requires much testing on large systems.

Well, you probably have a difficult system. Did you do lots of control experiments? Did you make sure that your model of Al-doped graphene itself gives predictions that agree with expt or intuition? Did you make sure you can accurately model an H2O molecule on a simpler surface, say pure Al or pure ...