[gmx-users] replica exchange doubt

[Andrea Carotti]

Hi all gmx-ers,
I have a doubt concerning the REMD setup. Let's say I want to use 12 cpus to 
make a REMD at 2 different temp 300 and 400K of the same system.
Should I prepare every tpr file with the -np option set to 6?
and then run the mdrun with -np 12 -multi -s 300.tpr 400.tpr -replica 
X -reseed?
The last doubt: is it possible/supported to make a REMD with an Umbrella 
sampling (a force between 2 centers of mass)associated?
Thanks a lot
Andrea