[gmx-users] Umbrella Sampling tutorial

[shahab shariati]

Dear Justin

Thanks for your reply.

You are right. I should  not extrapolate too literally from your tutorial
to my system.

But, I have a general question:

There is 2 groups in COM pulling method (reference group + pull group).

If I want to use pull_geometry = distance, so, I should fix reference group
to be immobile. Is it true?

On the other hand, I want to know exactly using position restraining on
reference group is optional or mandatory in COM pulling method?

Best wishes