[gmx-users] Rigid structure and flexible structure present in sing system

[Luke Goodsell]

Hi,

For a while I've been looking for a way to include a rigid
(macromolecular) structure and a flexible (small-protein) structure in
a single system and have not had much success.

I looked for a way to apply a different set of constraints to each
structure, but couldn't find one. I looked into modifying the topology
file, but the only method I could find was to artificially increase
the mass of every atom in the rigid structure and this does not save
any computing time.

Does anyone know how I can fix the relative co-ordinates of one
structure and only calculate the MD of another?

Any constructive criticism (even if to inform me that I'm doing
something ridiculous) is very gratefully received.

Kind regards,
Luke