Fatbands for Si

Take a look at the .fdf file. You will see three new lines:

WFS.Write.For.Bands T             # For fat-bands analysis
Wfs.band.min 1
Wfs.band.max 8

These tell the program to output the eigenvectors for the "band" states
specified in the BandLines block.

We are now going to produce a number of .EIGFAT files which contain
*both* the eigenvalues and the projection weight for each orbital
that we specify.


 Rename the si_fatbands.bands.WFSX file to 'si_fatbands.WFSX'.

 Execute the "fat" program with the fatbands.mpr file as input. We
 must leave out the .mpr extension:

    fat fatbands

 Now process the EIGFAT files:

eigfat2plot fatbands.fatbands_Si_3s.EIGFAT > 3s.dat
eigfat2plot fatbands.fatbands_Si_3p.EIGFAT > 3p.dat
eigfat2plot fatbands.fatbands_Si_3d.EIGFAT > 3d.dat

 Plot with gnuplot, with typical commands:
#

plot "3s.dat" using 1:2:(4*$3) with points pt 6 ps variable  
replot "3p.dat" using 1:2:(4*$3) with points pt 6 ps variable 

(or use the fatbands.gplot script: gp fatbands.gplot)

If we take the "density of states" of the "fat-bands", taking
into account the weight of each orbital, we will get the
"projected DOS" (pDOS) on each orbital. In fact, the file fatbands.mpr
can be used as-is with the 'mprop' program to generate the
files needed to plot the pDOS:

   mprop fatbands

You can plot some of the curves with the pdos-Si.gplot script.

