A statistical interpretation of Bader's definition of interatomic surface

Bader's definition of interatomic surface is here analyzed and interpreted in semiclassical statistical terms. By using Thomas-Fermi approximation for the electron density, we show that the partitioning of the whole system in statistical subsystems, which are in mutual equilibrium at each surface of separation, is consistent with Bader's partitioning of atoms in molecules. That is to say that Bader's interatomic surfaces define self-contained sta tistical entities in equilibrium with the surrounding system. (C) 2001 Else vier Science BN. All rights reserved.