I noticed the Modify and Extend section of the manual doesn’t include the several virtual “clear” methods defined in atom_vec.h. Are these safe to implement as far as calls in other parts of the code are concerned? I’ve only noticed it called in verlet.cpp; which would suit my objective if it was only called there.
When you say “safe to implement”, I presume you mean in a new atom style.
That is where the code for a force_clear() method from atom_vec.h lives.
That is certainlly safe to do.
If you mean invoke those methods in other places besides where
LAMMPS does now, e.g. when clearing all forces in Verlet, then
it may not be safe. E.g. you could lose partial forces already computed
if you invoke it at the wrong place in a timestep.