Purpose of pw2gw.x:
Optical properties in single-particle approach (Fermi Golden Rule).
Interface with GW and excitonic codes.
The code computes and writes ("matrixelements" file) the optical matrix elemenents in the
dipole approximation.
The code computes the imaginary part of the dielectric tensor xx, yy and zz ("epsX.dat", "epsY.dat",
"epsZ.dat") and the average ("epsTOT.dat")
Structure of the input data:
============================
&INPUTPP
...
/