Hi all!
I have to create a rigid body made by two differents group of atoms. From the fix-rigid documentation I used:
group grains union gran1 gran2
fix body grains group 2 gran1 gran2
However I have this error
ERROR: One or zero atoms in rigid body.
That’s no possible because I verified the presence of the atoms. What could be the problem?
thank you in advance for your help.
Giuseppe