Search found 7 matches

by gswylq
Wed Jun 09, 2021 7:01 pm
Forum: Response calculations
Topic: PAW+DFPT+GGA has unreasonable energy values
Replies: 3
Views: 419

PAW+DFPT+GGA has unreasonable energy values

Dear everyone, I calculate the Se2Mo elastic constants and piezoelectric properties using the PAW+DFPT+GGA(Se.GGA_PBE-JTH.xml,Mo.GGA_PBE-JTH.xml). However the results give some unreasonable energy values as below. The errors are also reported in the forums (https://forum.abinit.org/viewtopic.php?f=1...
by gswylq
Wed May 12, 2021 7:02 am
Forum: Other tools and postprocessing in ABINIT
Topic: abipy fold2Bloch
Replies: 2
Views: 1601

Re: abipy fold2Bloch

Hello developers, With some hit and try I was able to get the Brillouin zone path sorted out but I can unfold the bands when spin-orbit coupling is turned on. Is that feature not implemented in abipy? Also my conduction bands are not clearly visible. Any idea how do I improve those? File attached o...
by gswylq
Sat Dec 01, 2018 10:28 am
Forum: Response calculations
Topic: DDB file does not contain GS etotal
Replies: 1
Views: 836

DDB file does not contain GS etotal

Hi everybody, I am calculate the polarization, elastic constants and piezoelectric properties. I have obtained the correct results and are published several years ago throuth the anaddb in the abinit-7.6.3. But I do not obtain the results when I use the anaddb in the abinit-8.10.1. The input file fo...
by gswylq
Tue May 12, 2015 2:23 pm
Forum: Link to other codes
Topic: virtual crystal approximate
Replies: 2
Views: 2492

Re: virtual crystal approximate

The VCA is a rather severe approximation and in my experience gives good results less often than not. You would probably be better off studying a disordered system via the special quasirandom structures approach or some other method to build an alloy model. We are very much obliged to you for your ...
by gswylq
Mon May 11, 2015 5:02 am
Forum: Link to other codes
Topic: virtual crystal approximate
Replies: 2
Views: 2492

virtual crystal approximate

Dear all i am calculating PbTi(1-x)Zrx.Using default algalch algorithm, I don't obtain the correct ground state of PbTi0.5Zr0.5 (the total energy of P4mm structure is higher than that of R3m phase). Is there other algorithms included in abinit for the mixing atoms? Ramer (Physical Review B, 62(2), R...
by gswylq
Mon Jul 28, 2014 5:45 pm
Forum: Other tools and postprocessing in ABINIT
Topic: the phonon dispersion curves and the force constants
Replies: 0
Views: 1282

the phonon dispersion curves and the force constants

Dear all I'm trying to run the APPA, provided in abinit-7.8.2 package, for the analysis of Molecular Dynamics output files. The phonon density of states (VDOS) is obtained by using post-processing APPA, but the phonon dispersion curves and the force constants are not achieved. 'Phonon spectrum obtai...
by gswylq
Tue Jun 17, 2014 2:36 am
Forum: Response calculations
Topic: Positive frequency at Gamma for cubic BaTiO3
Replies: 0
Views: 1786

Positive frequency at Gamma for cubic BaTiO3

I'm trying to compute the phonon frequencies at Gamma for materials such as cubic BaTiO3, which is reported in literature to have a negative frequency of about 200cm-1 at Gamma. However, the calculation results are different from that of the literature (Lattice dynamics of BaTiO3, PbTiO3 and PbZrO3:...