SMTG-Bham
How to shift density of states
Dear Alex, I am plotting bands and dos in one plot. I see, my DOS is slightly shifted towards the +ve y-axis. I mean, VBM and VBM for bands and DOSs are not falling on the same point. I want to shift the default DOSs with the difference in Fermi_energy of band and doss. How can I do it?
This is the correct behaviour if the DOS includes broadening. Do you see it with a tetrahedron-method DOS?
I used the below INCARs
-
INCAR.scf ISMEAR = 0
SIGMA = .05 IBRION = -1 -
INCAR.HSE (used WAVECAR from step 1) IBRION = -1 ISMEAR=-5 SIGMA=0.01
That does look like a tetrahedron-method DOS, so this isn't due to smearing.
The Fermi energy of a non-self-consistent band structure calculation isn't really meaningful, but the energy levels should be consistent with a DOS calculated on the same density.
I wonder if it was shifted by self-consistency with more k-points. I see HSE mentioned so presumably these are self-consistent hybrid-DFT calculations with zero-weighted k-points for the band structure. Did you also zero-weight the DOS k-points? (Actually I'm not sure if Sumo really supports that, any idea @utf?) How well-converged is the self-consistent k-point mesh?
Another thing to check: which k-point has the VBM in the DOS? (You should be able to check with sumo-bandstats.) Is it definitely a point that appears in the band structure? (Usually it is Gamma and the answer is "yes" but there are exceptions...)
I used SCF k-mesh with 0.022piAng^(-1) for SCF in both cases. Although, "zero-weighted k-points" were used for SCF and NSCF for band structure calculations while for DOS, a regular k-mesh was used.
Hole effective masses: m_h: -4.394 | band 100 | [0.50, 0.00, 0.00] (M) -> [0.00, 0.00, 0.00] (\Gamma) m_h: -6.520 | band 100 | [0.50, 0.00, 0.00] (M) -> [0.00, 0.00, 0.00] (\Gamma)
Electron effective masses: m_e: 30.467 | band 101 | [0.00, 0.00, 0.00] (\Gamma) -> [0.50, 0.00, 0.00] (M) m_e: 2.760 | band 101 | [0.00, 0.00, 0.00] (\Gamma) -> [0.50, 0.00, 0.00] (M)
For DOS, I used gamma-centered k-mesh K-Spacing Value to Generate K-Mesh: 0.020 0 Gamma 4 4 1 0.0 0.0 0.0
for band structure, I used additional zero-weighted k-points.
I am attaching the plot. band.pdf
Hmm, that certainly does look like a shift in the energy reference. Can you have a look at the reported Fermi energy of your band structure and DOS calculations and see if they differ by a similar amount?
I think bandplot relies on the energy levels being consistent between calculations. It's strange that they would be so different for such a flat band structure.
I have checked the Fermi energy in both the cases, band &dos, and they differ by a small amount. I wanted to shift the doss by this difference from terminal.
On Mon, Dec 5, 2022, 8:13 PM Adam J. Jackson @.***> wrote:
Hmm, that certainly does look like a shift in the energy reference. Can you have a look at the reported Fermi energy of your band structure and DOS calculations and see if they differ by a similar amount?
I think bandplot relies on the energy levels being consistent between calculations. It's strange that they would be so different for such a flat band structure.
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We do not currently provide a command-line argument to apply this shift, it is expected that the DOS and band-structure calculations will be consistent.
It is quite strange that the Fermi energies would be different from calculations with the same "active" k-points, are you sure they are both using the same Gamma-centered 4x4x1 mesh and the SCF is converged?
This seems to be a bug that the command sumo-bandplot can not set the fermi energy to the same point that the band is set.
