摘要

Chemists have long searched for descriptions of atoms in molecules. A new model of atoms in molecules (AIM) is advanced, which shows that the atomic realm in a molecule is a subspace governed by its nucleus as a 3D attractor of the electron force lines defined by the negative gradient of the potential acting on one electron in molecule (PAEM), which is represented and calculated via ab initio methods. In this article, we demonstrate how the molecular space is partitioned into atomic realms and how the atomic charges in this PAEMAIM method are worked out. Atomic charges for more than 210 molecules and clusters were determined by integrating the electron density over individual atomic realms with our program. Notably, such atomic charges are nearly independent of the basis set used. The atomic charges obtained by PAEMAIM have good correlations with the Allen and Pauling electronegativity differences. Furthermore, charge transfer in prototype hydrogen bonding clusters, (H2O)(2), H2O-HF, and (HF)(2), was investigated with this method. In brief, the atomic charges calculated by PAEMAIM are reasonable and significant for further exploration and practical applications.