[Pw_forum] negative a2F(w)/w

[Ali Tavana]

I know my system is instable, but calculation for the stable systems takes 160 days for each q point on a 8 core machine!! In the other hand some people have published a Nature article about the superconductive properties calculation of that instable system with your code. Any way, thank you for your answer.

> 
> As discussed, many times in this forum, as well as in many
> textbooks,  
> negative squared ferquencies are a signal of a mechanical
> instability.  
> Are you sure that you want to spend a lot of computer
> resources  
> calculating the supercondictive properties of an instable
> (and, hence,  
> non-existent unless very special conditions occur) system?
> SB
>