quantum-espresso/Gamma

2003-01-10

This directory contains a Gamma-only (k=0) version of pw.x,
using only half G-vectors and performing two fft's at the
same time whenever possible. It is faster and leaner than
the ordinary pw.x version, but it can be used only for k=0 
sampling of the Brillouin Zone. Only Davidson diagonalization 
is implemented (CG and DIIS are not). It should have otherwise 
all the functionality of the normal version.

This directory contains also a Gamma-only, q=0 version of
the phonon code, called "raman". It works in conjunction
with the Gamma-only version of pw.x. Uses a conjugate-
gradient algorithm for the solution of linear-response
equation. Hopefully useful for normal mode calculations in
molecules. Does not work with ultrasoft pseudopotentials.

The "raman" code can also calculate Raman coefficients with 
finite differences (experimental). 

Installation:
  compile pw.x first
  cd Gamma
  make lib
  make pw.x
  make raman (if desired)
Usage:
  Input data for the ordinary versions of pw.x and ph.x should
  work also for pw.x and raman in this directory