ABINIT Discussion Forums

Dear Payam,

You mean : the alchemical mixing of pseudopotentials ?
If so, yes, it should work for phonons ...

Best,
X

Dear Matthieu and Matteo,

Interestingly, Guillermo pointed this problem to me a few days ago, because he has been
rewriting whole sections of the ionmov/=0 part of ABINIT. It is in the pile of things that
he will be looking at, during the next weeks (months ?)...

Best,
X.

Dear Mamikon,

You can define sine or cosine additional potentials (or a mixture) for a well-defined
wavevector, using vprtrb and qprtrb input variables. The gradient of the potential
is the electric field ...

Best,
X.

Another possibility would be to disable the plugins,
see an example in
doc/config/build-examples/bb_xeon-gfortran4.4_coba2_woplugins.ac

Best,
X

Dear Vivek, Well, nothing is coded to do this. The most powerful constraint specifier that is present in ABINIT is based on the wtatcon input variable and associate variables : m If there is a reference that describe how you would like to have it done, you might communicate it ... then we will see w...

Dear Carmine,

You could also modify your input parameters, following the document
doc/users/tuning.txt .

Best,
X

1st TYC workshop on Energy Materials - 2nd Announcement This two-day workshop brings together experimentalists, theorists and computational scientists working in the broad area of energy materials. -Materials for hydrogen and energy storage -Materials for (photo)-electrochemical energy conversion -M...

Dear Guangfu Luo,

The computation of Raman intensities with spin-polarized insulating systems
is not completely finished in v6.0 . It might be available soon, in ABINITv6.2 ,
if we solved the last remaining bug(s).

Best,
X

Dear Igor, As discussed at the CECAM tutorial in Lausanne with you, a few weeks ago, this was indeed a bug... ABINIT versions before 2006 worked just fine for ZrO2 , but a bug had been introduced then. This bug has been fixed in ABINITv6.0.4, available today. I hope you will be able to correctly rep...

Dear ham, You cannot expect to learn the basic things about the DFT and plane wave by using the ABINIT forum ... As mentioned in m you should make some effort by yourself. I cut and paste the relevant section : "Before following the tutorials, you should have read the "new user's guide&quo...

Dear R_S

As mentioned in
http://www.abinit.org/documentation/hel ... lcome.html
you should read some basic material about DFT + planewaves.

Best regards,
X

Dear ham,

As mentioned in
http://www.abinit.org/documentation/hel ... lcome.html
you should read some basic material about DFT + planewaves.

Best regards,
X

Dear Gaoyang, In principle, ABINIT is OK to compute phonon spectra for magnetic materials, and there are examples in the tests provided with the ABINIT package. However, some problems have been reported recently with some antiferromagnetic compounds. So, you might try, and report problems (or try to...

Has anybody already used ABINIT to study heterogeneous catalysis ?
I know the strengths of ABINIT are not in this area, but
a reference to a published paper would be nice ...
Xavier

Dear Mutta, Alchemical mixing of pseudopotentials is a very primitive technique to try simulate alloys. For certain pairs of pseudopotentials, the result is quite decent (even in case of heterovalent species, which is quite surprising), but for some other pairs of pseudopotentials, the results are d...

See http://www.abinit.org/developers/abinit ... -of-merges
X

Dear Jarvis,

You can find an example of the use of prtstm in tests/v4/Input/t46.in
Specifically, concerning your problem, set
prtden 0

Best,
X

Dear BMalvandi, In order to get the phonon frequencies of cubic LaCoO3, you are NOT supposed to move the atoms by hand, be it one or more. You should simply define the set of perturbations, using rfatpol and rfdir. Please, read carefully the tutorials, and also see the examples input files in the AB...

Dear Mutta,

Alchemical mixing, as coded in ABINIT, cannot be used with PAW.

That's life ...
X

Dear Mutta, You write : "The input variables related to the construction of the alchemical Ba(0.25) Sr(0.75) potential will be : npsp 4 znucl 8 40 56 38 ntypat 3 ntypalch 1 mixalch 0.25 0.75 for doped Ba/Sr" This is right, but npsp 4 znucl 82 40 22 8 ntypat 3 ntypalch 1 mixalch 0.2 0.8 wil...

Dear BMalvandi, Matthieu is right, your error comes from using xcart instead of xred . Indeed, by using your input file, with xcart replaced by xred : xred 0.2500 0.2500 0.2500 0.7500 0.7500 0.7500 0.0000 0.0000 0.0000 0.5000 0.5000 0.5000 0.1982 0.3018 0.7500 0.8018 0.6982 0.2500 0.3018 0.7500 0.19...

Dear Malvandi,

Could you post your entire input file, as well as the relevant part of the output file ?
Thanks !
X

Dear Cheti2010,

It is possible to have ABINIT input ixc=11 (GGA-PBE) while the pseudopotential has not been obtained
using this exchange-correlation functional. However this is not consistent.
You should have look at M. Fuchs et al, Phys. Rev. B 57, 2134 (1998)

Best wishes,
X

OK, thanks, corrected in v6.0.4
X

Dear Thomas, Even without considering the magnetic characteristics, your input file is wrong : - With natom 2, defining one Fe atom and one O atom, you will describe FeO, not Fe2O3 . If you want to have ABINIT generate the full primitive cell from its irreducible part, you should rely on the use of ...