ABINIT Discussion Forums

Hi Joe, Sounds like you have sorted things out in principle at least. It is a bit disappointing that we only get 5-6 digits, but perhaps that's inevitable for delicate calculations like elastic constants. We should be able to symmetrize them after the fact, though, and impose all digits being equal,...

Hi Seba,

the code will give you a default number of bands which is number of electrons / 2 (for spin) + 10% or so. Here we set it by hand to get only the occupied bands (for an insulator this is fine). The number of valence electrons are 3 and 5 for the 2 species, so 8 / 2 = 4

Hi Xing, you can use a _centered_ default grid (shiftk 0 0 0 nshiftk 1) of any density, including 5 5 5. The _optimal_ grid for BCC systems uses 2 shifts and has to be even (see paragraph under shiftk in the input variables web site) - this gives you the best quality integral for a given number of i...

Hello "q",

thanks - I have added this to the latest developer branch. Should be out in the next-next release 8.6 in a few months.

Hi Nancy,

non collinear magnetism works fine. For slightly canted materials it is delicate, and has been cleaned recently. Try the latest versions in norm conserving pseudopotentials: the PAW + non collinear canting can go to 0 spuriously in some cases.

I do not see a good reason for a strong difference (how much?) - your question is more about physics and xc than about the code. The PBEsol should only change a little the exchange part of pbe to be better for 3D solids (instead of molecules as in PBE): your layers are intermediate in dimensionality...

Hi Joe! love it when you cite me... Do you understand why the fft grid changes (ecutsm or different set of k points or k+q points?) I suspect internally somewhere it is still using a different grid. Anything fishy in your system (non collinear magnetism, parallelism...) - do you have a minimal input...

You are running the optic executable? This runs RPA sums over states, not Berry phase, I think. Your iscf -3 is a ddk calculation, which is an analytical perturbation wrt k. Your post is not explicit enough: need details on input output versions etc... See the netiquette. Some possibilities: * are y...

You have to be more specific with what you want: |psi_n,k|^2(r) is the density in real space corresponding to a single band and k point. It can be obtained from the cut3d utility. The normal rho(r) is periodic, so it does not have a k dependency, but it does have a reciprocal space representation in...

You can try to increase pawovlp to 50 % or so and see what happens - you don't have to change it at each step. If it ends up with a physically unreasonable situation you can check it yourself. Your set of constraints may make it quite hard to converge though. Also check out the recently developed io...

yes - you can define

natom 2
ntypat 2 # 2 atomic types
typat 1 2 # one atom of each type
znucl 14 14 # both silicon

and in the files file you put 2 psp files.

The CML support of abinit has been removed - it was out of sync with the evolution of the CML format. See the new list of input variables

http://www.abinit.org/doc/helpfiles/for ... ables.html

Hi Antonio,

part of the scan should be available through the libxc interface, once they update it (I think this is done).

The rVV10 is not implemented as far as I know, however. Abinit implements van der Waals in the Grimme, TS (of sorts), and DF styles:

http://www.abinit.org/doc/helpfiles/for ... tml#vdw_xc

You can look at the source code for the optic executable. The first thing it does is read in the files and create the pmat matrix elements you want. You could add fortran lines there to dump the matrix elements to file, or use it directly inside optic (depends what you want to do with them).

Hello Boubacar, your WFK file is probably corrupted somehow. As your k-point is towards the end, the header may be intact but not all of the file (or it may have been truncated because your disk quota ran out?) Other possibility: was it made on the same system as the cut3d you are running? The binar...

PS: Atsushi Togo has just confirmed he will also make a direct abinit interface for phono3py (should be soon).

See https://atztogo.github.io/phono3py/
https://atztogo.github.io/phonopy/

Dear Narges, I am not sure I understand your question entirely, but here goes. Your quality factor has to do with the zero frequency limit of the ratio involving the real and imaginary parts of epsilon_0, correct? Typically the intrinsic IR reflectivity spectrum is actually quite good without the br...

Dear Matthieu I am one of user abinit code. I want to quality factor by abinit code. I know quality factor is equal inverse dielectric loss tangent (tan δ = ε2/ε1). ε2 , ε1 are real and imaginary part dielectric. I should used equation 8 of attached 33.pdf for obtaining ε2 , ε1. this relation said t...

Hello Elena,

I started this implementation a while ago (2009). It has stopped for the moment, as there were pseudopotential-specific terms I started on which were complex and I didn't have time to do things cleanly.

Best

Matthieu

Hello Temok, Have a look at the paper of Monkhorst and Pack (H. J. Monkhorst and J. D. Pack, Phys. Rev. B 13, 5188 (1976)) for a classic example. The idea is to optimize the precision of an _integral_ in k space (Etot, Force, stress...) with respect to the number of reduced k-points. If you use symm...

Hi Masoomeh, your run is not able to print the output WFK file at the end of dataset 1. This seems to be a network disk related issue (not abinit related) - perhaps you can post your job submission file and "files" file, but normally only your local sysadmin can fix this kind of thing for ...

Your configuration apparently did not link properly to the MPI version (or the MPI version itself is not correctly compiled).

Hello, the server links are being updated. In the meanwhile you can find the 32 bit old binaries at m Please note that more recent versions of abinit provide many more features and stuff (PAW...). The optimal solution if you really want to work under windows is to install something like cygwin (m wi...

Hello, the symmetry operations are in the same order as in the main abinit output, and in the DDB file. I agree it is easier to have them on hand, and will add their printing to the anaddb log file for abinit v8 (to be released in a few months or so). There are a number of tools that analyze the irr...

please read and follow the nettiquette on the main forum page.

You should probably not be running anaddb in parallel. In particular if you are using a version before 7.10, and for most purposes there is no need.

Try to run without the NL part to make sure your main ddb is correct.