[QE-users] Puzzle in doing band unfolding

[Pietro Bonfa']

Dear Zongyi Wang,

I think you're right, the issue seems to be in the visualization step.

I recently noticed that the overlapping of colormaps and lines no longer 
works as expected in gnuplot. For example, the following line:

splot './SC/Fe.dat' binary record=(2001,-1) format='%double' u 
($1*TPIBA):2:3 notitle, './BC/Fe.bands.dat' u 1:2:2 w p ps 0.1 notitle

does not display the colormap generated from Fe.dat. Removing the second 
plot (the one using Fe.bands.dat) produces the correct colormap.

A much better option is, in my opinion, using python and matplotlib. You 
can find an example in `examples/Si_FCC`.

It's difficult to debug further without the input and output files.

Best regards,
Pietro


On 7/14/25 06:55, wangzongyi via users wrote:
> Dear all
> 
>    I am trying to do band unfolding calculation, but after I read the 
> tutorial online, I only find the auxiliary software unfold-x provided by 
> Dr.Pietro Bonfa’.I followed the tutorial and calculated my system step 
> by step but I'm stopped by some problem.
> 
>    Firstly, I calculated the primitive cell in the following sequence
> 
> 
> /*mpirun -np 32 pw.x < scf.in > scf.out*/
> 
> */mpirun -np 32 pw.x < bands.in > bands.out/*
> 
> */mpirun -np 1 bands.x < pp.bands.in > pp.bands.out/*
> 
> 
> Then I obtained VSe2_bands.dat.gnu which describe the band structure in 
> its' two columns. After that I followed the tutorial for the supercell 
> calculation. The supercell I choose is 2*2*1. I calculated by the 
> following step:
> 
> 
> /*mpirun -np 32 pw.x < scf.in > scf.out*/
> 
> */mpirun -np 1 unklist.x < unklist.in > unklist.out/*
> 
> */mpirun -np 32 pw.x < bands.in > bands.out/*
> 
> */mpirun -np 1 unfold.x < unfold.in > unfold.out/*
> 
> 
> After that, the file VSe2_Unfolded_SPFN.dat generated successfully. But 
> when I use gnuplot to draw the picture, something went wrong. My gnuplot 
> code is in the following lines
> 
> 
> /*set terminal pngcairo enhanced font "Verdana,10"*/
> 
> */set output 'output.png'/*
> 
> */TPIBA=1.1845361/*
> 
> */set pm3d map interpolate 2,2/*
> 
> */set yrange [-3.5:0.5]/*
> 
> */#splot 'VSe2_Unfolded_SPFN.dat' binary record=(121,-1) 
> format='%double' u ($1/TPIBA):2:3 notitle/*
> 
> */splot 'VSe2_Unfolded_SPFN.dat' binary record=(121,-1) format='%double' 
> u ($1/TPIBA):2:3 notitle, '../KGM/VSe2_bands.dat.gnu' u 1:2:2 w p ps 0.1 
> notitle/*
> 
> */set output/*//
> 
> 
> 
> 
> and the output png file is like this
> 
> 
> It shows that the two data file are not compatible and the figure is 
> really terrible.
> 
> 
> What should I change? Could you please help me?
> 
> 
> Thank you very much!
> 
> 
> Zongyi Wang
> 
> 
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