[QE-users] Getting rid of negative values of phonon frequencies for lambda.x calculation

[mkondrin]

Dear QE developers and users!

I encountered a problem calculating Tc of certain material. During 
calculations of its phonon dispaersion I obtain negative (bat small in 
absolute value) of three acoustic modes in Gamma point (all other modes 
are positive). So, this prevents obtaining Tc values of this material 
due to the diverging logarithm of negative values. How to circumvent 
this issue? I simply delete negative sign of this modes in elph file. Is 
it OK?

Thank you in advance.

Sincerely yours,
M. V. Kondrin