Evaporate with pair/gran/local dump of force

Hello everyone.

I've been working on a pebble bed for which I'm trying to do some numeric experiments with stiff, brittle, ceramic pebbles. As a first-order test of the bed, I'm using the fix/evaporate command to remove pebbles from the bed and watch how the new ensemble evolves under load. I'm also monitoring pebble contact forces with the compute of pair/gran/local. I've run into a bit of a snag.

There are no errors when the code runs. However, after pebbles are 'evaporated' out of my system, the compute of forces still lists the entire original ensemble of contact forces. I.e. I begin with 5414 particles, evaporate 30, then the dump still lists 5414 IDs and the associated contact forces -- but there's just the 5384 that exist in the liggghts log. When I go to plot results, I end up plotting for 5414 pebbles when I know the system has fewer - this is not right. I need to fix this.

The documentation for evaporate says that the command saves a scalar of the total particles removed from the system. But no mention of evaporated pebble ID. If I can't change what is dumped from my results, I thought I could at least find the ID of the pebbles that had been removed and just manually ignore them from my post-processing.

These are the pertinent lines of code


compute fc all pair/gran/local id pos force
...
dump fcevap all local 50000 post/Evap/forcechain/dump.fc.*.liggghts c_fc[1] c_fc[2] c_fc[3] c_fc[4] c_fc[5] c_fc[6] c_fc[7] c_fc[8] c_fc[10] c_fc[11] c_fc[12]
fix evap all evaporate 10000 3 evapreg 1001
run 100000


If anyone has any insight into this I would be very grateful. I'm not a pro at dissecting the source code (well, not even an amateur) so I've been stuck with this problem and turn to the forum for help.