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electronic structure coming out to be metallic while it should be semiconducting

Posted: Thu Dec 26, 2024 9:43 am
by fakir_chand1

Dear VASP admin,
I have been computing electronic band structures of transition metal dichalcogenides monolayers and results aren't satisfactory. Materials that have been reported to be semiconductors by other VASP using authors, sometimes come out to be metallic in my calculations. For example i tried finding out electronic band structure of PtSSe bilayer. I have attached the incar files of each step and POSCAR and POTCAR files as well. K-points and k-path were generated using vaspkit.
Please help us find out what we can do to improve our results.
Many thanks in advance,
Team Kurukshetra :) :)


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Sun Dec 29, 2024 9:14 am
by alex

Hi there,

some outputs would be of great help, too! ;-)

BR

alex


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Mon Dec 30, 2024 6:54 am
by fakir_chand1

Dear Alex,
I have attached the output files, however CHGCAR file was too large to be attached. I hope OUTCAR files would be sufficient.
Thanks,
Team Kurukshetra :) :)


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Mon Dec 30, 2024 1:22 pm
by alex

No worries Team Kurukshetra,

the OUTCAR contains sufficient information to move one step forward:

In your case: Pt is formally Pt(IV), so you should carry out a spin-polarized calculation, e.g., with ISPIN = 2
in INCAR. This should already help a lot.

Good luck,

alex


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Tue Dec 31, 2024 5:02 am
by fakir_chand1

thank you very much alex.
We will let you know soon how it turns out :) :)


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Thu Jan 02, 2025 5:30 am
by fakir_chand1

Dear Alex, i tried with ISPIN=2, but the bandgap is still metallic. It gave warning about assigning default values of MAGMOM tag but I did not know what to do about that, so I let it have the default values. I have attached the input and output files of my latest calculations.
Kindly look into it and please help us.
All of the kurukshetra folks would be greatful to you :) :)


Re: electronic structure coming out to be metallic while it should be semiconducting

Posted: Thu Jan 02, 2025 1:45 pm
by alex

Hello again,

I think I got it. Check the OUTCAR
WARNING: type information on POSCAR and POTCAR are incompatible
POTCAR overwrites the type information in POSCAR
typ 2 type information: S Pd
WARNING: type information on POSCAR and POTCAR are incompatible
POTCAR overwrites the type information in POSCAR
typ 3 type information: Se S

and then
grep TIT POTCAR
TITEL = PAW_PBE Pt 04Feb2005
TITEL = PAW_PBE Pd 04Jan2005
TITEL = PAW_PBE S 06Sep2000
TITEL = PAW_PBE Se 06Sep2000

Not exactly what you are heading for, hmm?! :)

Take these warnings of VASP seriously, they are good advice. Also try to automize the creation of these files you don't want to touch in some ways.

Good luck!

alex

PS: it seem's Pt likes to stay non-magnetic.