Problem with fix evaporation

Dear Lammps users,

I am modelling water evaporation on the water/Pt system. For this purpose, I made a simulation box with a size of 80 80 300 (see the attached file). Pt atoms are located at the bottom of the box and water molecules are on the Pt surface. Everything was good in a closed system. Now, I want to remove the water molecules (vapour) from the top of the simulation box. That is why I used fix evaporate command as below.

group water type 1 2

region del block EDGE EDGE EDGE EDGE 100 300 units box

fix 5 water evaporate 100 30 del 38277 molecule yes

However, nothing is removed from the box during the simulation. I even changed the evaporation region to a larger domain (for example: block EDGE EDGE EDGE EDGE 40 300 units box), but the total number of atoms remains constant. I would be grateful if you help me to fix this issue.

Thanks,
Atefeh

water_Pt.jpg

sorry, but i cannot reproduce this. i just added your commands (with some necessary adjustment of the block region) to the input in the rdf-adf example and it works just fine. every 100 steps 30 atoms are removed. this is with the 18 Feb 2020 release.

axel.