Search found 66 matches

by new_986
Mon Mar 16, 2020 11:08 am
Forum: Input file
Topic: Optimization of tetragonal perovskit???
Replies: 7
Views: 190

Re: Optimization of tetragonal perovskit???

Dear Nawzad, You need to extend the cell and break the symmetry by moving the atoms accordingly, is it what you did? Best wishes, Eric Dear Eric I have already these following extensions for perovskite 0.0 0.0 0.0 0.5 0.5 0.51 0.5 0.5 0.0 0.5 0.0 0.5 0.0 0.5 0.5 and 0.0 0.0 0.0 0.5 0.5 0.51 0.5 0.5...
by new_986
Mon Mar 09, 2020 11:44 am
Forum: Input file
Topic: Optimization of tetragonal perovskit???
Replies: 7
Views: 190

Re: Optimization of tetragonal perovskit???

Dear Eric
I have already tried extensions but still no relaxation happens...
Thanks a lot

Nawzad
by new_986
Tue Feb 25, 2020 9:32 am
Forum: Input file
Topic: Optimization of tetragonal perovskit???
Replies: 7
Views: 190

Re: Optimization of tetragonal perovskit???

Dear Nawzad, You indeed break the symmetries with the cell parameters but you kept the atomic positions to high-symmetry ones and it sounds your system goes back to cubic if all the atomic positions are in high-sym (and I would say as it should be for perovskites without epitaxial constraints). Alt...
by new_986
Tue Feb 25, 2020 9:19 am
Forum: Input file
Topic: MIXing coefficients for ALCHemical potentials [SOLVED]
Replies: 8
Views: 188

Re: MIXing coefficients for ALCHemical potentials [SOLVED]

The code stops at the level of the parser hence it does not enter the SCF cycle. As mentioned in the error message: Found the token NPSPALCH in the input file. This name is not one of the registered input variable names (see https://www.abinit.org/doc). NPSPALCH is an internal variable (the name st...
by new_986
Tue Feb 25, 2020 9:16 am
Forum: Input file
Topic: MIXing coefficients for ALCHemical potentials [SOLVED]
Replies: 8
Views: 188

Re: MIXing coefficients for ALCHemical potentials [SOLVED]

Dear Nawzad, To me it is not possible that the program runs a few relaxation steps without complaining about the input file and stops about a wrong input variable after passing the initial input variables test... Could you send your output file and eventually the log file? Thanks, Eric Dear Eric Yo...
by new_986
Mon Feb 24, 2020 11:47 am
Forum: Input file
Topic: Optimization of tetragonal perovskit???
Replies: 7
Views: 190

Optimization of tetragonal perovskit???

Dear all Greetings I am trying to do optimization for tetragonal phase of a perovskite specifically CsPbCl3 I give spgroup input variable which 140 due to papers but my run stops and gives me the following error: --- !ERROR src_file: symatm.F90 src_line: 201 mpi_rank: 13 message: | Largest error (ab...
by new_986
Mon Feb 24, 2020 8:28 am
Forum: Input file
Topic: MIXing coefficients for ALCHemical potentials [SOLVED]
Replies: 8
Views: 188

Re: MIXing coefficients for ALCHemical potentials [SOLVED]

Dear Eric Thanks for the reply the error message is the following --- !ERROR src_file: chkvars.F90 src_line: 403 mpi_rank: 13 message: | Found the token NPSPALCH in the input file. This name is not one of the registered input variable names (see https://www.abinit.org/doc). Action: check your input ...
by new_986
Sun Feb 23, 2020 10:29 am
Forum: Input file
Topic: MIXing coefficients for ALCHemical potentials [SOLVED]
Replies: 8
Views: 188

Re: MIXing coefficients for ALCHemical potentials [SOLVED]

Dear Jmb
Thanks for the reply
I have checked the right version inputs and it is same but still the computer stops after a couple times of optimization
Regards

Nawzad
by new_986
Tue Feb 18, 2020 9:17 am
Forum: Input file
Topic: MIXing coefficients for ALCHemical potentials [SOLVED]
Replies: 8
Views: 188

MIXing coefficients for ALCHemical potentials [SOLVED]

Dear all I want to study the effect to doping Sn into CsPbCl3, here is my input # DATASET configuration ndtset 1 # Atomic Structure #----------------- acell 5 5 5 Angstr natom 5 ntypat 3 typat 1 2 2 2 3 rprim 1 0 0 0 1 0 0 0 1 xred 0.0 0.0 0.0 0.5 0.0 0.5 0.0 0.5 0.5 0.5 0.5 0.0 0.5 0.5 0.5 prtcif 1...
by new_986
Tue Oct 22, 2019 8:35 am
Forum: Theory
Topic: theory of optic tutorial?
Replies: 2
Views: 380

Re: theory of optic tutorial?

Thanks Nick
by new_986
Mon Jan 28, 2019 9:13 am
Forum: Theory
Topic: theory of optic tutorial?
Replies: 2
Views: 380

theory of optic tutorial?

Hello everybody
What theory used to calculate linear optical properties in tutorial optic in abinit?

Thanks
by new_986
Mon Dec 17, 2018 10:08 am
Forum: Ground state
Topic: Phase transition under pressure?
Replies: 4
Views: 968

Re: Phase transition under pressure?

ebousquet wrote:Dear Nawzad,
I would say the most general directions to break all the symmetries.
Best wishes,
Eric

Thanks Eric
I will try that

Nawzad
by new_986
Sat Dec 01, 2018 10:57 am
Forum: Ground state
Topic: Phase transition under pressure?
Replies: 4
Views: 968

Re: Phase transition under pressure?

Dear Nawzad ABINIT performs the structural optimizations by keeping the symmetries of the initial structure. It seems that your system has the cubic symmetry (Pm-3m). If you do not allow ABINIT to leave this space group, it is normal that the system remains always cubic. Simply break the symmetries...
by new_986
Fri Nov 09, 2018 8:59 pm
Forum: Input file
Topic: Atomic structure relaxation [SOLVED]
Replies: 4
Views: 866

Re: Atomic structure relaxation [SOLVED]

Dear Nawzad, Thanks so much for your reply. What I meant was something similar to having optcell=2. However, optcell=2 allows for full relaxation subject to symmetry imposed in the initial guess structure. Here I do not know the symmetry groups of the materials of interest and wish to find those ou...
by new_986
Mon Nov 05, 2018 11:32 am
Forum: Input file
Topic: Atomic structure relaxation [SOLVED]
Replies: 4
Views: 866

Re: Atomic structure relaxation [SOLVED]

Dear cgs12
see input variables opcell and ionmove ...
best wishes

Nawzad
by new_986
Mon Nov 05, 2018 10:05 am
Forum: GW
Topic: pressure dependence of band gap [SOLVED]
Replies: 5
Views: 3275

Re: pressure dependence of band gap [SOLVED]

Dear Nawzad, calculate total energy as a function of pressure for both cubic and orthorhombic structures. there will be crossover at some pressure (you said experimental one is 0.4GPa). You have to use the bandgaps corrosponding to minimum energy structure at each pressure. regards -rajaraman Dear ...
by new_986
Fri Nov 02, 2018 9:47 am
Forum: Input file
Topic: How I get optimized structure in tetragonal phase
Replies: 12
Views: 6005

Re: How I get optimized structure in tetragonal phase

Hello
I know this post is not new, but have you guys solved the problem? because I have the same problem with tetragonal perovskite structure. it is turning to cubic
any help plz?

Nawzad
by new_986
Thu Nov 01, 2018 8:39 am
Forum: Input file
Topic: Optimization of the tetragonal phase?
Replies: 0
Views: 471

Optimization of the tetragonal phase?

Hi everybody I am trying to optimize the tetragonal phase under 5 GPa pressure, but the relaxed atomic coordinates and optimized unit cell dimensions turns to cubic phase (c/a=1), while it should stay a tetragonal the following is my input file #Datasets: convergence on ecut #ndtset 16 #Cell and ato...
by new_986
Mon Oct 29, 2018 8:42 am
Forum: Ground state
Topic: Phase transition under pressure?
Replies: 4
Views: 968

Phase transition under pressure?

Hello everybody I am trying to investigate properties of a perovskite compound, experimentally phase undergoes through transition at 4 GPa, I also increase the pressure and I do relaxation to the unit cell for all pressures up to 10 GPa, but my structure keeps the same which is cubic (doesn't underg...
by new_986
Tue Oct 02, 2018 12:39 pm
Forum: GW
Topic: pressure dependence of band gap [SOLVED]
Replies: 5
Views: 3275

Re: pressure dependence of band gap [SOLVED]

Dear Nawzad, calculate total energy as a function of pressure for both cubic and orthorhombic structures. there will be crossover at some pressure (you said experimental one is 0.4GPa). You have to use the bandgaps corrosponding to minimum energy structure at each pressure. regards -rajaraman Dear ...
by new_986
Fri Sep 14, 2018 11:56 am
Forum: GW
Topic: pressure dependence of band gap [SOLVED]
Replies: 5
Views: 3275

Re: pressure dependence of band gap [SOLVED]

Dear Eric Yes band gap reduces with increasing of pressure...but I have seen in references, for example, for CsPbI3 phase transition happens from cubic to orthohombic before 0.4 Gpa, But I have increased pressure up to 1 Gpa, my question is, How I know when phase changes in abinit? Thanks for replyi...
by new_986
Tue Aug 28, 2018 11:02 am
Forum: GW
Topic: pressure dependence of band gap [SOLVED]
Replies: 5
Views: 3275

pressure dependence of band gap [SOLVED]

Hi all I want to calculate band gap of a perovskite structure at different pressures, first I did cell optimization of different pressures, then I used optimized lattice constant and relaxed atomic coordinates as inputs to calculate band gap As it's known band gap should increase with increasing pre...
by new_986
Fri Aug 03, 2018 10:23 am
Forum: Response calculations
Topic: Elastic properties
Replies: 7
Views: 2722

Re: Elastic properties

Hi Nawzad, what does "gamma point is not relaxed" mean? Do you get something absurd, 10% off, 20%? Also, first tell us how close you are in lattice and structure. Some datasets may have "finished" all of their iterations, but if the tolerance is not satisfied the results will be...
by new_986
Mon Jul 30, 2018 10:39 am
Forum: Response calculations
Topic: Elastic properties
Replies: 7
Views: 2722

Re: Elastic properties

Dear Matthieu
Thanks for the reply
My results ( Elastic Tensors) do not agree with other available results ...
I have did convergence to ecut, kpt and pawecutdg...
I will increase nband and above input variables...
but optimization finishes without any warning .
Thanks


Nawzad
by new_986
Sun Jul 29, 2018 8:42 am
Forum: Response calculations
Topic: Elastic properties
Replies: 7
Views: 2722

Elastic properties

Hi everybody I am trying to calculate elastic properties of CsPbBr3, I do relaxation to the cell using the following input: ndtset 2 # There are 2 datasets in this calculation # Set 1 : Internal coordinate optimization ionmov1 2 # Use BFGS algorithm for structural optimization ntime1 15 # Maximum nu...