Recently I am getting some confusing results by using SIESTA. While plotting a band structure I am getting a band gap which is quite large. However, when I am trying to plot its corresponding total partial density of states (PDOS), I can clearly see that there is no existence of any band gap. But interestingly the component PDOS are giving the required band gap. The problem is with the total PDOS. Do any of you have any idea about these kinds of results.
Could it be that your fermi-levels are differently aligned in the two cases?
But how do I know that. I have adopted that Fermi energy which is written in the band structure data file...
For the energy bands, you must take into account all de high simmetry points (k-points) in the irreducible portion of the Brillouin zone.
It seems that another direction is needed, you should check that all the high symmetry points of the first Brillouin zone were taken into account. The upper valence bands are not at the zero energy.
No more high symmetry points are needed. The pristine band structure matches very well with that with the published result. The upper valence band need not to be situated at the zero energy.
You need to select correct number of k-points for your model. Please note that DOS/PDOS is sensitive to k-points.
Please take a look:
https://www.researchgate.net/post/Inconsistency_between_DOS_and_Band_structure
My band structure matches very well with the published results...So I am quite confident about the k-points which I have taken for my calculation...
If you are sure that the bands are correct, then the DOS are wrong.
I am not familiar with siesta, but perhaps you should post the settings you used to run the calculation. I know VASP can produce strange results if the INCAR file is not correct.
I have already posted the settings here that I have used to run the calculation.
If the DOS and bands are produced in one single calculation, then I am afraid something is terribly wrong with your SIESTA installation. In case it are different calculations, please make sure that both are done properly.
For example if you need to provide a charge density and wave-function coefficient file to start the calculation of the bands and dos, make sure they are
* the correct ones
* the same for bands and DOS
* read correctly by SIESTA
It looks a bit like you performed the DOS with random wavefunctions.
Also check if the DOS and band-structure file give the same fermi level (which should be the top of your bands in the bandstructure in case of a semiconductor...in case of a metal, you are either missing bands or high-symmetry directions of your system(Which in case of a supercell with for example a defect is different from that of the pristine material))
Finally, your plot does not show all PDOS components, so the total DOS can still be consistent with the PDOS.
Dear All,
I am calculating PDOS of LaF3 doped with Eu and Tb (DFT+U calculation) but when I am plotting pdos, I am not getting conduction band density of states properly. I have attached here my pdos graph. My Fermi level is at zero eV and in INCAR, I gave energy range EMIN and EMAX -20 and 20 eV respectively. Still I am not getting dos upto 20 eV energy range Where is the problem ? Thank You to All
Shilendra
you can check the broadening parameter for PDOS to known more information .
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