I was trying to do fermi surface calculation for SILICON(Si) with vaspkit and I followed the instruction as given on tutorials. According to tutorial first I generated the KPOINT file using 261 command and after that I did a vasp calculation. After that I used vaspkit again to generate FERMISURFACE using 262 command but I got an error.
Error: No Bands Across Fermi Energy. Is it a semiconductor?
Please help me out. Thanks in advance.
Hello, Himanshu Sharma. Silicon has no Fermi surface. If you want plot the isosurface of the energy level located above CBM or below VBM, you can set the value of Fermi energy in the FERMI_ENERGY.in http://fermi_energy.in/ (the second line).
I was trying to do fermi surface calculation for SILICON(Si) with vaspkit and I followed the instruction as given on tutorials. According to tutorial first I generated the KPOINT file using 261 command and after that I did a vasp calculation. After that I used vaspkit again to generate FERMISURFACE using 262 command but I got an error.
Error: No Bands Across Fermi Energy. Is it a semiconductor?
Please help me out. Thanks in advance.
Thanks for the reply, Sir. Actually I need the file fermisurface.bxsf which generate through this process and I have tried for another material ZrNiSn and I am getting the same error. And another point I would like to mention, while using the vaspkit with command 262, I got another file name fermi_energy in which fermi energy was mentioned but it could not generate fermisurface.bxsf and I got the error about which I mentioned above.
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Thanks for the reply, Sir. Actually I need the file fermisurface.bxsf which generate through this process and I have tried for another material ZrNiSn and I am getting the same error. And another point I would like to mention, while using the vaspkit with command 262, I got another file name fermi_energy in which fermi energy was mentioned but it could not generate fermisurface.bxsf and I got the error about which I mentioned above.
You need to shift the Fermi energy manually in the second line of FERMI_ENERGY.in http://fermi_energy.in/ file to ensure several band cross this value.
But sir, Is it ok to do so? Because the fermi energy that is currently written on FERMI_ENERGY.in is matching with OUTCAR file.
And if it is ok to change, what value should I choose? Can I set the fermi energy equal to VBM?
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But sir, Is it ok to do so? Because the fermi energy that is currently written on FERMI_ENERGY.in is matching with OUTCAR file.
And if it is ok to change, what value should I choose? Can I set the fermi energy equal to VBM?
Sorry Sir, I am not able to understand your point. As I have mentioned above, I need FERMIENERGY.bxsf file which can be produced from vaspkit and there is no such thing mention on vaspkit tutorial that a "FERMIENERGY.bxsf FILE can not be generated for a semiconductor". I need this file for a further calculation.
I dont want to plot anything with this file. I need this file as an input file for further calculation. And I am still not able to produce this file with the help of vaspkit.
Last edit: Himanshu Sharma 2022-07-12
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Soory Sir, I am not able to understand your point. As I have mentioned above, I need FERMIENERGY.bxsf file which can be produced from vaspkit and there is no such thing mention on vaspkit tutorial that a "FERMIENERGY.bxsf FILE can not be generated for a semiconductor". I need this file for a further calculation.
I dont want to plot anything with this file. I need this file as an input file for further calculation. And I am still not able to produce this file with the help of vaspkit.
I was trying to do fermi surface calculation for SILICON(Si) with vaspkit and I followed the instruction as given on tutorials. According to tutorial first I generated the KPOINT file using 261 command and after that I did a vasp calculation. After that I used vaspkit again to generate FERMISURFACE using 262 command but I got an error.
Error: No Bands Across Fermi Energy. Is it a semiconductor?
Please help me out. Thanks in advance.
Last edit: Himanshu Sharma 2022-07-11
Hello, Himanshu Sharma. Silicon has no Fermi surface. If you want plot the isosurface of the energy level located above CBM or below VBM, you can set the value of Fermi energy in the FERMI_ENERGY.in http://fermi_energy.in/ (the second line).
Thanks for the reply, Sir. Actually I need the file fermisurface.bxsf which generate through this process and I have tried for another material ZrNiSn and I am getting the same error. And another point I would like to mention, while using the vaspkit with command 262, I got another file name fermi_energy in which fermi energy was mentioned but it could not generate fermisurface.bxsf and I got the error about which I mentioned above.
Please rename FERMI_ENERGY as FERMI_ENERGY.in http://fermi_energy.in/.
Thanks for the suggestion but problem remainsas it is. Still getting same error.
You need to shift the Fermi energy manually in the second line of FERMI_ENERGY.in http://fermi_energy.in/ file to ensure several band cross this value.
But sir, Is it ok to do so? Because the fermi energy that is currently written on FERMI_ENERGY.in is matching with OUTCAR file.
And if it is ok to change, what value should I choose? Can I set the fermi energy equal to VBM?
You cannot plot the Fermi surface for semiconductors. You can only plot the energy surface below VBM or above VBM.
Sorry Sir, I am not able to understand your point. As I have mentioned above, I need FERMIENERGY.bxsf file which can be produced from vaspkit and there is no such thing mention on vaspkit tutorial that a "FERMIENERGY.bxsf FILE can not be generated for a semiconductor". I need this file for a further calculation.
I dont want to plot anything with this file. I need this file as an input file for further calculation. And I am still not able to produce this file with the help of vaspkit.
Last edit: Himanshu Sharma 2022-07-12
It is common sense that semiconductor has no Fermi surface. You should use a metal such as copper to test this utility.
Got it. Thank you so much sir for all the suggestions and discussion.