Transferability of Pseudopotentials

Pseudopotentials have become an important tool for the calculation of electronic and structural properties of molecules and solids. The extensive experience with pseudopotentials shows that they accurately describe the properties of matter. It remains to be understood, however, why the same pseudopotential can describe atoms in different chemical environments. We show that this transferability is related to the existence of a region around the nuclei where the charge density is practically independent of the chemical environment.