Run qe2pert.x and perturbo.x on silicon with spin-orbit coupling

The input files can be found in the directory *“pw-ph-wann”*. Remember to run scf, nscf and Wannier90 calculations that include spinor-related variables. Once the DFT and DFPT calculations are completed, we run `qe2pert.x`

to generate *‘prefix’_epr.h5*. In the input file for `qe2pert.x`

(*“qe2pert/pert.in”*) the user does not need to specify any spinor-related variables since `qe2pert.x`

is able to detect that spin-orbit coupling (SOC) was used in DFT. Here is the input file (*pert.in*):

```
&qe2pert
prefix='si'
outdir='./tmp'
phdir='../pw-ph-wann/phonon/References/save'
nk1=8, nk2=8, nk3=8
dft_band_min = 1
dft_band_max = 32
num_wann = 16
lwannier=.true.
/
```

The input file is similar to the one for silicon without SOC (*“example02-silicon-qe2pert”*, link). We only need to double the number of Wannier functions (num_wann variable) and DFT bands (dft_band_min and dft_band_max) in the input file.

The input files for `perturbo.x`

are also similar to the silicon calculations without SOC, except for the band range given by dft_band_min and dft_band_max. Each calculation is the same as in the silicon example without SOC.