# What is the meaning of EATOM tag in the POTCAR files of VASP?

I am wondering what is the meaning of EATOM tag in the POTCAR files of VASP. What is its relationship with the energy of an isolated atom ? is it the same ?

EATOM is not considered as energy of isolated atom, you can check energy by taking large (10x10x10) simulation box. This tag has no use for general user as this is mainly used by developers during pseudo-potential creation.