[lammps-users] shake for methane!

Dear all, I want to simulate several CH4 molecule using shake; but this seems not possible because LAMMPS allows for the following kinds of clusters to be constrained: one central atom bonded to 1 or 2 or 3 atoms.
Any idea?

Cheers

N.

That's a current limitation of LAMMPS. You can model
them as rigid bodies if you like with fix rigid.

Steve

Ok, in fact I was thinking about rigid bodies but if I have a huge number of CH4 the MPI_Allreduce should become take a significantly part of time because there are a great number of rigid body.

Cheers

I would try it - see how it does. The only other
option is to extend fix shake, which would be
non-trivial.

Steve