[gmx-users] freezegrps changing coordinates in NPT simulations

[jwillcox at andrew.cmu.edu]

Hello again,

I'm running a simulation with graphene as a periodic molecule.  I've
frozen the carbons in place in the mdp file using:

freezegrps               =  CG_CE
freezedim                = Y Y Y

but when I run an NPT simulation, the entire system shrinks (including
moving the carbons closer together) until it crashes.  Everything works
fine for NVT and minimization.

Are there any tricks to freezing groups in NPT simulations?

I've also attached my mdp file.

Thank you!

Jon