I make a new fix command to add atoms frequently. So there will be two parts inside my simulation box ,one is addatom and another one is the original substrate which I create before adding atoms.I want to use fix_nvt in order to move the addatoms but not to the substrate,because the temperature is different between these two part. But I did not find anyway to control the temperature of the addatoms independently. And the only way to control the temperature of addatoms is using the fix_nvt to "all" group. Is there any suggestion for me to use fix_nvt to the addatoms independently?
Thank you very much.