On 12/10/20 2:44 PM, Altair Hernández wrote: > I'm trying to use the *IMP.pmi.tools.set_coordinates_from_rmf *to start > modelling a complex from a previous modelled frame.
This will only work if the topologies of the two complexes are the same.
> In a first step, I > set the whole structure as a single rigid body and perform 100 rex > frames. In the second step I want to use the frame 99 of this modelling > as starting point, but now I want to divide the structure into several > rigid parts and super rigid bodies.
This won't work because the RMF file doesn't save the global coordinates of each particle in the rigid body - it saves the reference frame of the body and the body-frame coordinates (relative to that frame) of each particle. So there's only one reference frame in the RMF (for the one rigid body in the original modeling) and you're trying to apply it to multiple rigid bodies. If you have the same set of particles in both cases, you should be able to read in their global coordinates, then map them to body-frame coordinates for each new rigid body. (There are methods in the RigidBody class to do this.) Or you could just set all your new rigid bodies to have the same reference frame. But this would be an "exercise for the reader" - there is no code in PMI (to my knowledge) to do this.
Another option would be to write out PDB or mmCIF files for each subunit from your first simulation, then use these in the topology file for the second one.
Ben