Fix deform on rigid bodies

Dear lammps-users,

I am applying shear on a system containing both rigid bodies and solvent molecules which are not. Unless I used ‘remap x’, there would always be zero potential as well as error thermodynamic output.

Since I am using dpd/tstat, therefore the system is updated under NVE ensemble instead of fix nvt/sllod. I’ve tried to apply shear on only solvent system with ‘remap v’ as well as on the whole system with ‘remap v’, they didn’t work until I changed ‘remap v’ into ‘remap x’.

Can anyone kindly remind me of what’s going wrong here please?
Thanks in advance,

You should read the discussion of remapping on the fix
deform doc page. There are several issues to be
aware of, including for rigid bodies. For a liquid, you
should use remap v, but you have to be careful not
to deform so rapidly that the liquid can't keep up
with the shearing box. You basically want the liquid
shearing at the same rate that the box is deforming.


Hi Steve,
Thanks for your reply.
I understand that I have to use ‘remap v’ for the fluid. However, as long as I am using ‘remap v’, I can’t get correct thermo output – zero potential energy, erroneous temperature. That’s what I am trying to figure out. I attached a snapshot of the screen output for a clearer understanding. Thanks again!


I guess your dynamics are bad - there are lots of reasons
that could be, including shearing too quickly.


Hi Steve,

After using the latest version of lammps, it’s working perfectly. Sorry for not realizing this earlier. But thanks a lot for your help!