[gmx-users] Density

[Mark Abraham]

Carla Jamous wrote:
> Hello,
> I'm experiencing some difficulties with gromacs. In order to control my 
> system's density, I have to use g_energy or g_density.

Those tools report density-related quantities, they do not control it.

> However, when I use g_energy, in my list, "Density" doesn't appear.

g_energy doesn't report the density if you have a constant-volume 
simulation (but grompp probably reported it when you generated the .tpr)

> Else, if I use g_density, it needs a file traj.xtc which I don't have.

Per Erik's point, you can usually use any coordinate file or trajectory 
file.

Mark

> So please can anyone tell me how to check my system's density in gromacs?
> 
> Thank you
> 
> Carla
>