[FLASH-USERS] Modified ideal gas EOS implementation

[Klaus Weide]

On Mon, 27 Apr 2020, Acharya, Nitish wrote:

>  My ion pressure goes negative which is desirable for my problem because i want to simulate tension in the material. To mitigate the issue of imaginary sound speed, i wanted to correct the sound speed as well.
> 
> Can i not have negative ion pressures?

Apparently not. I think that would require significant changes in the 
Hydro unit.

Klaus