I am currently studying the aspect of inducing the emission of large secondary clusters from a target through the keV impact of C60 collisions with a solid.
Our current interest is temporal evolution of sputtered outgoing large, very hot clusters. In this regard, I am wondering if it is possible to exclude the most of target atoms after a certain period of time of calculation (like, for example, the option to remove from the calculations all atoms below some predefined height above the target) and continue to calculate only the clusters of interest.
In my current approach I isolate the cluster, then use its geometry as input for the next run, gradually equilibrating the cluster as a microcanonical ensemble to desired (taken from the previous run) temperature. Obviously, this does not seem to be the optimal approach.
Dear Axel, Thank you very much for your quick response. Does this command allow to retract from the calculations all yellow colored atoms in the situation as it is shown on the attached figure and to include only the atoms above an appropriate Z-coordinate value. Probably I’ve missed something but I did not see it in the LAMMPS explanations for that command “thermo_modify”. Apreciate your response. Victor
delete particles outright from a simulation with delete_atoms
keep one set of particles static while letting them continue to exert forces on other particles, by restricting your integrator fix to only particles in a “mobile” group
make a group of particles move “as a block”, either without torque (using fix aveforce to just impose an average force) or with torque (using fix rigid to create a rigid body which can rotate under torque)
