I would like to perform shear simulations of systems containing fluid
particles and solid particles constructed with fix rigid. From the
documentation on fix deform for rigid particles,
"If a fix rigid <fix_rigid.html> is defined for rigid bodies, and remap
is set to x, then the center-of-mass coordinates of rigid bodies will be
remapped to the changing simulation box. This will be done regardless of
whether atoms in the rigid bodies are in the fix deform group or not.
The velocity of the centers of mass are not remapped even if remap is
set to v, since fix nvt/sllod <fix_nvt_sllod.html> does not currently
do anything special for rigid particles. If you wish to perform a NEMD
simulation of rigid particles, you can either thermostat them
independently or include a background fluid and thermostat the fluid via
fix nvt/sllod <fix_nvt_sllod> ."
Can this be explained in more detail? Should one apply fix deform to
all particles, or should just the solvent particle coordinates be
deformed, and what remapping should be used? What does it mean to
thermostat the rigid particles independently? They're rigid particles;
why should they be thermostatted? Since I'm using fluid particles,
should I apply fix nvt/sllod to the fluid and fix nve to the solid
particles and rely on the fluid particles to shear the solid particles?
Does this introduce errors when the rigid particles cross the sheared
boundary without having their velocities remapped?
Thanks in advance,
David R. Heine
Senior Research Scientist
Corning, NY 14831