[Pw_forum] Problem in QHA

[Paolo Giannozzi]

On Wed, 2013-04-10 at 04:18 -0700, zafar rasheed wrote:
> 
> First I performs 1. scf calculation then 2. phonon calculation and
> produce ZnO1S.fc file then 3. This ZnO1S.fc file use in QHA code and
> run this QHA code.

the QHA code is currently not maintained. It shouldn't be difficult
anyway to look into the various steps performed by the QHA codes and
scripts and see where the NaN (Not a Number: the result of a forbidden
operation, like a divide by zero) start to appear. A likely candidate
for trouble is the T=0 case: notice that it is the only case where
E_internal and C_v are NaN

P.