
This example shows how to use pw.x and band_interpolation.x 
to calculate the band structure of Silicon using PBE and 
hybrid PBE0 functional.

pwscf.xml files are compressed (as filexml.tar.gz) in each folder

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in pbe_reference_bands/ the reference PBE bands have been computed with 

${QE}/PW/src/pw.x    < pbe.scf.in   > log.pbe.scf.in   
${QE}/PW/src/pw.x    < pbe.nscf.in  > log.pbe.nscf.in  
${QE}/PW/src/pw.x    < pbe.bands.in > log.pbe.bands.in 
${QE}/PP/src/bands.x < pbe.pp.in    > log.pbe.pp.in    

and the plottable PBE band structure is in pbe.bands.dat.gnu

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in pbe_fourier/ the interpolated PBE band structure has been computed 
by performing a simple SCF 

${QE}/PW/src/pw.x    < pbe.scf.in   > log.pbe.scf.in

and then interpolating the eigenvalues read in pwscf.xml 
with the fourier-diff method

${QE}/PP/src/band_interpolation.x    < fourier-diff.in   > out.fourier-diff.in

and fourier method

${QE}/PP/src/band_interpolation.x    < fourier.in   > out.fourier.in

The two band structures are stored in files fourier-diff.dat and fourier.dat, 
respectively, and can be directly compared with the reference pbe.bands.dat.gnu.

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in pbe0_fourier/ the interpolated PBE0 band structure has been computed 
similarly to the PBE case 

${QE}/PW/src/pw.x    < pbe0.scf.in   > log.pbe0.scf.in

${QE}/PP/src/band_interpolation.x    < fourier-diff.in   > out.fourier-diff.in

${QE}/PP/src/band_interpolation.x    < fourier.in   > out.fourier.in

and two band structures are stored in files fourier-diff.dat and fourier.dat,
respectively.

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in pbe_idw/ the (low quality) interpolated PBE band structure has been computed 
with the (very simple) idw and idw-sphere methods 

${QE}/PW/src/pw.x    < pbe0.scf.in   > log.pbe0.scf.in

${QE}/PP/src/band_interpolation.x    < idw.in   > out.idw.in

${QE}/PP/src/band_interpolation.x    < idw-sphere.in   > out.idw-sphere.in

and two band structures are stored in files idw.dat and idw-sphere.dat, 
respectively.

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