quantum-espresso/examples/example24

This example shows how to use pw.x, efg.x and nmr.x to calculate the nmr 
parameters (chemical shift and quadrupolar parameters) on quartz.

The calculation proceeds as follows (for the meaning of the cited input
variables see the appropriate INPUT_* file)

1) make a self-consistent calculation for the willing structure
   (input=quartz.scf.in, output=quartz.scf.out).
   for further examples, see example01

2) for the quadrupolar parameters, extracted from the electric field gradient
   tensor, you should use the post-processing code efg.x which will use the 
   charge density computed in 1) to perform the calculation.
   In order to reconstruct the all-electron response from a pseudo-potential 
   calculation, you need extra files corresponding to the all-electron and 
   pseudo- atomic wavefunctions produced during the generation of the 
   pseudopotential. (see file_recon in atomic code).
   (input=quartz.efg.in, output=quartz.efg.out).
   NB: this calculation is possible only for norm-conserving pseudopotential
   for the moment.