Search found 13 matches

by tangds
Tue Dec 29, 2020 1:47 pm
Forum: Ground state
Topic: Thermal conductivity calculation using abinit+phono3py
Replies: 4
Views: 222

Re: Thermal conductivity calculation using abinit+phono3py

Can you try to increase the value of boxcutmin from 2 to e.g. 4? We found some difference when comparing Abinit DFPT phonons with phonopy finite difference method with Abinit forces and we managed to make the phonopy results agree with DFPT by increasing boxcutmin. BTW: Are you using ADDGRID=True (...
by tangds
Tue Dec 29, 2020 1:46 pm
Forum: Ground state
Topic: Thermal conductivity calculation using abinit+phono3py
Replies: 4
Views: 222

Re: Thermal conductivity calculation using abinit+phono3py

Thanks for your reply. It is weird that abinit+phonopy can produce good phonon dispersion relations compared with vasp+phonopy, where the settings in calculating 2nd IFCs are exactly the same with those in 3rd IFCs calculations. The input file used for 3rd IFCs calculations is attached which takes 0...
by tangds
Thu Dec 24, 2020 2:11 pm
Forum: Response calculations
Topic: Finite electric field calculations with PAW
Replies: 0
Views: 74

Finite electric field calculations with PAW

Dear all, In calculations at finite electric fields, e.g., born effective charges calculations using finite difference methods, with paw, wrong forces are obtained while it is ok for psp8 pseudopotential case, based on referenced values of born effective charges. Is this bugs noticed and modified in...
by tangds
Sun Dec 20, 2020 6:47 am
Forum: Ground state
Topic: Thermal conductivity calculation using abinit+phono3py
Replies: 4
Views: 222

Thermal conductivity calculation using abinit+phono3py

Dear developers, I met the problem in calculating thermal conductivity using abinit+phono3py. The 3rd interatomic force constants are calculated using finite difference supercell method, in which the force for each displaced supercell is calculated using abinit. However, the thermal conductivity res...
by tangds
Thu Oct 08, 2020 8:56 am
Forum: Ground state
Topic: How to accelerate convergence in ground state calculations? [SOLVED]
Replies: 2
Views: 1147

Re: How to accelerate convergence in ground state calculations? [SOLVED]

Dear Dr. Eric,

Thanks for your reply.

Best,
Daosheng
by tangds
Thu Sep 10, 2020 1:50 pm
Forum: Ground state
Topic: How to accelerate convergence in ground state calculations? [SOLVED]
Replies: 2
Views: 1147

How to accelerate convergence in ground state calculations? [SOLVED]

Dear all, I am running a series calculations of ground state with 108 atoms using 48 cores (in a single node). The settings "autoparal and paral_kgb" are both used in input file. To get the convergence "toldfe=1e-10", about 50 steps are needed, which is quite large. Is it possible to accelerate conv...
by tangds
Fri Sep 04, 2020 2:20 pm
Forum: Response calculations
Topic: Relax structure at finite electric field [SOLVED]
Replies: 4
Views: 707

Re: Relax structure at finite electric field [SOLVED]

Dear Eric,

Thank you very much for your detailed reply. I got it how to relax structure at finite electric field now.
It is OK to relax both cells and atomic position, which I made a mistake.

Best,
Daosheng
by tangds
Fri Sep 04, 2020 9:40 am
Forum: Response calculations
Topic: Relax structure at finite electric field [SOLVED]
Replies: 4
Views: 707

Re: Relax structure at finite electric field [SOLVED]

Dear Professor, Actually, I want to obtain the optimized structure at finite electric field which can be used for further phonon calculations. The reduced E only supports cell relaxation without atomic position. So, how should we do to relax both cells and atomic positions at finite electric field? ...
by tangds
Tue Sep 01, 2020 9:47 am
Forum: Response calculations
Topic: Berry phase_new warning [SOLVED]
Replies: 6
Views: 633

Re: Berry phase_new warning [SOLVED]

Supplement for last post, zincblende GaN is polar crystal without spontaneous polarization.
by tangds
Tue Sep 01, 2020 9:43 am
Forum: Response calculations
Topic: Berry phase_new warning [SOLVED]
Replies: 6
Views: 633

Re: Berry phase_new warning [SOLVED]

Dear Professor, Thanks for your reply. The polarization in PAW and psp8 are nearly the same especially for ionic part while slight difference exits for electronic part. I calculated dielectric constant from the P(E) curve following the tutorial https://docs.abinit.org/tutorial/ffield/. I also checke...
by tangds
Mon Aug 31, 2020 8:24 am
Forum: Response calculations
Topic: Berry phase_new warning [SOLVED]
Replies: 6
Views: 633

Re: Berry phase_new warning [SOLVED]

Dear Prof. Verstraete, Thank you very much for your reply. Following your suggestions, I performed four group calculations including PAW+dfpt, PAW+finite_electric_field, psp8+dfpt, and psp8+finite_electric_field for born effective charges and dielectric constant. The primitive cell is optimized suff...
by tangds
Mon Aug 31, 2020 8:17 am
Forum: Response calculations
Topic: Relax structure at finite electric field [SOLVED]
Replies: 4
Views: 707

Relax structure at finite electric field [SOLVED]

Hi, I would like to consult how to relax the structure at finite electric field? My main purpose is to calculate thermal properties of GaN under electric field. So, I want to relax the structure at finite electric field. I modified the example for structure optimization calculation of wurtzite struc...
by tangds
Sat Aug 29, 2020 1:53 pm
Forum: Response calculations
Topic: Berry phase_new warning [SOLVED]
Replies: 6
Views: 633

Berry phase_new warning [SOLVED]

Hi, I met a problem in calculating born effective charges and dielectric constant of wurtzite GaN using a finite electric field calculation with PAW pseudopotential. The GaN is a polar crystal with spontaneous polarization. In calculation, there are many warnings like following statement: “berryphas...