Search found 19 matches
- Tue Jul 07, 2015 3:58 pm
- Forum: Ground state
- Topic: Projected DOS not normalized
- Replies: 2
- Views: 4550
Re: Projected DOS not normalized
Indeed. The weird result is that the plane-waves contribution to DOS is multiplied by the number of processors in PAW calculations (tested on the tpaw1_4 exercise of the PAW1 tutorial).
- Mon Jan 12, 2015 5:25 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Hello everybody. The thread was inactive for quite a long time. Any movements? Very recently, I've tested the DFPT phonon calculations for alpha-quartz at the LDA/PAW level with v7.8.2 and have obtained the same weird result: large negative frequencies. Obviously, the issue, which is the root of the...
- Mon Feb 03, 2014 10:03 am
- Forum: Response calculations
- Topic: Phonon calculation with DFT + U
- Replies: 2
- Views: 3437
Re: Phonon calculation with DFT + U
Hi Yes it is available using LDA+U only (not GGA+U). It works just like the tutorial on the abinit website except you'll need PAW dataset instead of pseudopotentials. Boris Am I right that PAW+DFPT does not work yet in 7.6.1 (see D.10 in release notes)? If so, the phonon calculations using PAW are ...
- Wed Jul 24, 2013 9:33 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
The NCPP input file for the phonons at Gamma attached; PSPs were taken from FHI database. At the end of the file you find extracts from abinit and anaddb outputs with the values of the phonon frequencies. As you see the ASR is not satisfied in the abinit output, while when anaddb has done its job th...
- Tue Jul 23, 2013 9:00 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Dear Boris, Thank you for the hints. The weird thing is that the ASR is obviously satisfied with NCPPs, while it does not with PAW. It seems to be strange because anaddb operates with a precomputed Hessian. I'll appreciate any feedback concerning the issue. Have a good holidays. Best regards, Konsta...
- Thu Jul 18, 2013 4:31 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
anaddb should give you a file with the extension ".freq". Do you have this file? If you do, could you please provide what is inside? anaddb produces a file with the extension PHFRQ. The file is attached (I've changed the extension to get the file attached). Could you please grep "box...
- Thu Jul 18, 2013 11:13 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
As for your results, something is troubling me. You said that you analyzed the frequencies with anaddb, but anaddb is supposed to impose the acoustic sum rule, therefore you should have the first three frequencies set to zero. Plus, what you are quoting in your posts look like the abinit results pr...
- Tue Jul 16, 2013 4:08 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Could you please try with ecut = 25 Ha and pawecutdg = 40 Ha? Results are: Phonon frequencies in cm-1 : - -4.067343E+02 -3.536478E+02 -3.402707E+02 -2.818307E+02 -2.100758E+02 - 4.004261E+01 4.529726E+01 1.446989E+02 1.820860E+02 1.861747E+02 One negative frequency less, but what is really the reas...
- Fri Jul 12, 2013 10:57 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Dear Boris, Some other hints: always use the latest version of abinit because the PAW+DFPT part still changes and set USEXCNHAT to 1. Also, phonon frequencies are strongly dependent on the quality of the ground-state wavefunctions, therefore you should converge your wavefunctions to at least TOLWFR ...
- Thu Jul 11, 2013 4:07 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Dear Boris, Thank you for the post. The phonon frequencies calculated at Gamma with PAW+DFPT are wrong because of the breaking of the acoustic sum rule. This is related to the fact that the system should be invariant by translation and it is actually not the case. The phonon frequencies therefore ne...
- Wed Jul 10, 2013 1:48 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
To know if this coming from pseudos, code or whatever, I did quickly a frozen phonon calculation (with phonopy) with your input files and your psp's and I don't have any instability: So this means that there is a problem somewhere with the DFPT (code, input file, compatibility with uspp, ...) that ...
- Fri Jun 28, 2013 2:42 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Results from 7.2.2 version are:
The same weird behaviour.
Nice WE to everybody.
Konstantin
Phonon frequencies in cm-1 :
- -4.024624E+02 -3.493627E+02 -3.338475E+02 -2.761988E+02 -2.032222E+02
- 2.762020E+01 2.815136E+01 1.416090E+02 1.776531E+02 1.814254E+02
The same weird behaviour.
Nice WE to everybody.
Konstantin
- Fri Jun 28, 2013 10:31 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Yes, these phonons sounds quite odd... Like that I cannot tell you what can be wrong, do you mind to put your output file in case I can see any trouble? PS: btw, did you try to run with 7.2.2 version instead of 7.2.1? Dear Eric, A set of input/output files is attached. What is a bit troubling to me...
- Wed Jun 26, 2013 1:53 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
These are the results for alpha-cristobalite with other PAW files. Parameters: ecut=30 Ha, geometry optimization with tolmxf=1.0d-6, SCF criterion tolvrs=1.0d-15 is identical in both the geometry optimization and response calculations. Phonon frequencies in cm-1 : - -4.024624E+02 -3.493627E+02 -3.33...
- Mon Jun 24, 2013 4:01 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
The atomic data coming from N. Holzwarth web site are known to be ecut consuming... I propose you to use the one from GPAW code: m Or the one coming from Rabe/Vanderbilt group (only PBE up to know, so DFPT is not yet working for GGA): m With these atomic data, you should get convergence with much s...
- Fri Jun 21, 2013 4:07 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
can you post your input file? I suppose that the request was for me. The input file for the phonon calculations is attached. The ecut is enormous (40 Ha) and was used just to test the convergence issue. The atomic PAW files are: Oxygen - m (LDA, Rc=1 Bohr) Silicon - m (LDA) Best regards, Konstantin...
- Fri Jun 14, 2013 10:56 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Hello Igor, Also, did you check the convergence wrt other parameters, like ngkpt? And also did you use the same parameters for the relaxation and for the phonon calculations? I use kprtlatt grid suggested by ABINIT, the convergence parameters are identical to those used in the geometry optimization....
- Thu Jun 13, 2013 5:02 pm
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
Re: PAW+phonons
Dear Eric, Since I did the calculations to test the capability of ABINIT, I did not test the convergence with ecut. The ecut used was 25 Ha with pawecutdg 50 Ha. The information in the atompaw database shows that such cut-off should be enough. By the way, increasing ecut to 30 Ha does not change the...
- Thu Jun 13, 2013 9:16 am
- Forum: Response calculations
- Topic: PAW+phonons
- Replies: 44
- Views: 47744
PAW+phonons
Hello everybody. Trying to test the phonon calculations with LDA + PAW I've encountered the following problem. Everything went well as soon as the calculations dealt with a small size cell system (such as Li2O). However, trying to test the calculation of phonons at Gamma for alpha-quartz and alpha-c...