I am calculating bandgap of LaVO4 doped with Eu with spin polarized from DOSCAR in VASP code. DOSCAR is showing many gaps in 2nd column between 1.992-2.007, 2.042-2.076, 2.118-2.140, 2.167-4.943 why so many gaps are coming.
I want to know what is the significance of all columns and what is the exact bandgap. I have attached INCAR and DOSCAR files here. Please open file in word pad. Thanks in advance !
Hi!
I might be a little late, but you maybe still need a tool for calculating bandgaps and I have one. I attach a python script that uses the OUTCAR file to calculate the bandgap. I use the OUTCAR mainly because that file is nearly always saved and the necessary information about occupation numbers and band energies is contained in it. Please refer to the script itself for more info, I hope it is sufficiently commented. If you have any more questions do not hesitate to ask.
Cheers, Michael
Please see the column descriptions given at the attached link (part of the very useful VASP Guide, which is freely available online). The second and third columns give the spin-up and spin-down DOS, and the fourth and fifth columns give the integrations of the spin-up and spin-down DOS. The gaps you describe indicate that there are some fairly localized states between the gaps.
To figure out where to find the band gap between occupied and unoccupied states, you'll need to know where the Fermi level lies, which is found in OUTCAR (search for the final E-fermi value).
You might also find the attached document useful. It's an appendix from my dissertation, written to help new VASP users quickly get started on modeling oxide slabs.
Good luck!
http://cms.mpi.univie.ac.at/vasp/vasp/DOSCAR_file.html
Hi!
I might be a little late, but you maybe still need a tool for calculating bandgaps and I have one. I attach a python script that uses the OUTCAR file to calculate the bandgap. I use the OUTCAR mainly because that file is nearly always saved and the necessary information about occupation numbers and band energies is contained in it. Please refer to the script itself for more info, I hope it is sufficiently commented. If you have any more questions do not hesitate to ask.
Cheers, Michael
Thank You Dear Michael Wolloch for your kind support.
I will try this script and if I face any problem I will ask you.
Dear Dr. Michael Wolloch you sent me python script for bandgap visualization in your above post. Today I downloaded it and I saw it is empty and showing 0 byte memory.
I think it is not uploaded correctly. can you send me corrected script again.
Thank you for your kind help and support always !
Shilendra
I need another help from you regarding bandstructure in my other question in below link.
https://www.researchgate.net/post/How_do_we_perform_plot_data_extracting_from_p4vasp
Hi!
I get the correct file with the link... However I will send you a message in a minute with the script attached. let me know if this works.
Now it is working properly and showing right bandgap. Here I want to ask one thing this script is applicable to all system like doped systems and also for hybrid functionals. I checked it for pure system with PBE functional.
Thank you for help and support
Shilendra
The script only uses the OUTCAR file, more specifically the listed band energies for each kpoint. The formatting of the OUTCAR does not change depending on the functional or doping, thus it should work for all systems. Please let me know if you run into problems for a specific system or VASP version,
cheers, Michael
I have plotted for both Eu spin-up and spin-down. Data is showing total 26114 lines in which half of them having two columns and after that remaining half values for Eu spin-up and Eu spin-down with three columns.
When I am plotting these values with 4 columns two for total bands and two for Eu bands corresponding values for Eu with non zero third columns. It is overlapping almost.
Bands are not looking as they are appearing in p4vasp software as I have attached jpeg.
I have attached my graph here and p4vasp graph.
Shilendra
Maybe because nearly all bands have some Eu states mixed into them? try plotting only lines with the third column over a certain threshold.
It might also work (e.g in gnuplot) to set the point size to correlate with the third column.
Hi Kuntal,
Same here. I also want to know the meaning of other numbers as well.
For the first line, the first two numbers (96) are the number of ions.
For the second line, I have no idea. But I noticed that the same numbers appear in the PCDAT file.
For the third line (1.000000000000000E-004), I believe this is the EDIFF setting. But I am not very sure.
For the sixth line, the 1st number (11.13275526) is the highest energy where the DOS is being evaluated, and the 2nd number (-64.9084116320000) is the lowest energy where DOS is being evaluated. Notice how the energy in the first line of TDOS is -64.908, almost equal to -64.9084116320000, If you check the last line of TDOS, the energy should be 11.133.
For the sixth line, I don't know what 1.000000 means.
Did you get information for other numbers?
Thank you very much.
Best,
Shaira
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