[Pw_forum] Some problems for lambda.x

[Paolo Giannozzi]

On Wednesday 06 April 2005 14:49, Shihn Lun wrote:

> I wanted to perform 'lambda.x' to obtain electron-phonon
> coupling information. But I got error messages,'NaN',
> in my output files.

as Eyvaz correctly observed, negative values of omega^2 at 
some q (likely at q=0) will yield a 'Not a Number' as a consequence
of a sqrt(omega^2) performed in the code. This is obviously a bug
and will be fixed. Note that the code is not really sophisticated and
may occasionally fail to give accurate results or even to work at all. 
Also note that the convergence of electron-phonon interaction
coefficients requires a lot of patience.

Paolo