yambo-py pdos not correct

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yambo-py pdos not correct

Postby HIMANIM » Wed Mar 29, 2017 8:11 am

Dear sir,

I was trying to run gs_si.py file in present in the tutorials folder in silicon section. I had run relax, scf, nscf, bands and orbital parts. I am getting correct result for band structure but when i am trying to plot the "si.pdos_tot" file present in bands folder to get the total DOS the result is not convincing. As shown in the band structure the valence band maxima is at 0 energy but the DOS is showing band gap flat at some value near 5 eV and that band gap is not matching with what we got in the band structure. Can you tell me what is the problem?

Regards,
Himani Mishra
IIIT Allahabad
HIMANIM
 
Posts: 21
Joined: Tue Jan 31, 2017 12:12 pm

Re: yambo-py pdos not correct

Postby miranda.henrique » Fri Mar 31, 2017 4:34 pm

Dear Himani,

The reason for this difference is that in the plot of the band-structure we shift the energies to make the fermi energy be 0.
This is not done in the output of projwfc.x .
A workaround to make the code not shift the bands is to add the following line (orbitals function in the gs_si.py):

Code: Select all
p_orb = [1,2,3,17,19,20]
[b]projection.fermi = 0[/b]
projection.plot_eigen(ax,path=p,selected_orbitals=s_orb,selected_orbitals_2=p_orb,size=40,cmap='RdBu')

Then you can compare directly the bands with the projected DOS

For your second question:
Keep in mind that this projected density of states is calculated only with values along the high-symmetry line used to calculate the bands.
To get a correct result you should use a regular k-mesh.

Regards,
Henrique Miranda
Henrique Pereira Coutada Miranda
Institute of Condensed Matter and Nanosciences
http://henriquemiranda.github.io/
UNIVERSITÉ CATHOLIQUE DE LOUVAIN
miranda.henrique
 
Posts: 16
Joined: Thu Jul 23, 2015 2:34 pm


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