Search found 10 matches

by jlb
Wed Jun 25, 2025 1:00 pm
Forum: General discussion
Topic: EPW given a wrong polaron localization and exchanged the atom index in psir_plrn.xsf
Replies: 3
Views: 1610

Re: EPW given a wrong polaron localization and exchanged the atom index in psir_plrn.xsf

Dear jack, Yes, the choice of the pseudopotential might affect the electronic structure, phonons, and the electron-phonon matrix elements; as a result it might indirectly influence the polaron formation energy as well. However, the differences should be quantitatively small, and no qualitative ...
by jlb
Wed Jun 25, 2025 10:57 am
Forum: General discussion
Topic: EPW given a wrong polaron localization and exchanged the atom index in psir_plrn.xsf
Replies: 3
Views: 1610

Re: EPW given a wrong polaron localization and exchanged the atom index in psir_plrn.xsf

Dear jack, From your input file I see that you are using a 6x6x6 k- and a 2x2x4 q-grid. The k- and q- grids need to be commensurate, and these are not, so epw1 should print an error message (as I have reproduced using your file). Please use commensurate k- and q- grids (e.g. 6x6x6k and 2x2x2q, and ...
by jlb
Wed Jun 25, 2025 7:17 am
Forum: General discussion
Topic: The polaron formation energy is curious
Replies: 2
Views: 1129

Re: The polaron formation energy is curious

Dear jack, The current implementation in the polaron module is based on the theory described in this reference: https://doi.org/10.1103/PhysRevB.99.235139 As you can see in Eq. (18), the theory assumes that the atomic configuration in the initial configuration (no extra added/removed electron) is ...
by jlb
Sat Jun 07, 2025 8:49 am
Forum: General discussion
Topic: Polaron formation energy
Replies: 1
Views: 7379

Re: Polaron formation energy

Dear Christoph, Thanks for pointing this out. The polaron formation energy is defined as the energy difference with respect to the periodic insulating crystal with one added/removed electron, so efermi_read should be kept to .false. as it is done by default. The code then sets to zero the KS energy ...
by jlb
Thu Nov 28, 2024 11:16 am
Forum: General discussion
Topic: The traped state of palaron in the band gap
Replies: 1
Views: 16794

Re: The traped state of palaron in the band gap

Dear Taifeng Liu, Thank you for your question. Note that in the current implementation the self-interaction is removed for the extra electron (or hole). This means that the polaron eigenvalue, with respect to the conduction (or valence) edge, should be accurate. The value of the band gap itself ...
by jlb
Fri Jul 26, 2024 4:07 pm
Forum: General discussion
Topic: plotting polaron
Replies: 1
Views: 11291

Re: plotting polaron

Hello Pravin Karma, You can get a better-looking figure by just changing the boundaries in VESTA; on the left-hand side, click "Boundary", and change the limits to x(min) =-0.5; x(max)=0.5; y(min)=-0.5; y(max)=0.5; z(min)=-0.5; z(max)=-0.5 Keep in mind is that when solving the polaron equations in a ...
by jlb
Mon Mar 18, 2024 6:08 pm
Forum: Running the code
Topic: Polaron self-consistent process fails
Replies: 1
Views: 9479

Re: Polaron self-consistent process fails

Hi Michael,

At the end of your slurm file I see that the number of requested CPUs is 192. In this example the k/q-grid is 4x4x4 so you can parallelize over 64 pools at most. Could you try reducing the number of CPUs / pools and see if the problem persists?

Best,
Jon Lafuente-Bartolome
by jlb
Fri Nov 24, 2023 1:46 pm
Forum: Running the code
Topic: Problem with calculating polaron equation
Replies: 3
Views: 32183

Re: Problem with calculating polaron equation

Dear Pravin, I agree with Sabya, this error occurs when the number of MPI processes is larger than the number of k-points in the fine grid (where the matrix elements will be interpolated and the polaron equations solved). In the school example (lif.epw2.in), nkf1=nkf2=nk3=4, so the fine grid ...
by jlb
Wed Oct 11, 2023 10:02 am
Forum: Running the code
Topic: Polaron: Error in getting the polaron wave function in real space
Replies: 2
Views: 15532

Re: Polaron: Error in getting the polaron wave function in real space

Dear Qiaolin, That is correct; In order to write the polaron wave function in real space, the Wannier functions in .cube file format are required. These can be written with EPW by setting the input variable wannier_plot = .true. (see https://docs.epw-code.org/doc/Inputs.html#wannier-plot and related ...
by jlb
Tue Aug 01, 2023 7:42 am
Forum: Running the code
Topic: polt the Ank.band.plrn
Replies: 1
Views: 14883

Re: polt the Ank.band.plrn

Dear leeru, The structure of the Ank.band.plrn file, ordered by columns, is as follows: # k-point index (k) # band index (n) # Kohn-Sham eigenvalue in eV (\varepsilon_{nk}) # Re[Ank] # Im[Ank] # Abs[Ank] You can plot this data using any software of your choice. Best regards, Jon Lafuente-Bartolome