ABSTRACT
The electromagnetic forces are responsible for keeping the atoms and molecules together. The electrostatic force is the dominant force in atoms and molecules, and magnetic force is only observable as small corrections. Electric and magnetic phenomena were unified by Maxwell equations, for example, in generation of electric energy by means of mechanic energy. However, electrostatic phenomena or magnetostatic phenomena can exist in isolation by Coulomb law and Biot-Savart law, respectively. R. F. W. Bader used the electrostatic formula to represent the interaction between one proton and one electron in a hydrogen molecule. Peoples shall use the same electrostatic interpretation to evaluate the strength of chemical bonds and intermolecular interactions, and also to relate this strength to the corresponding molecular energy. In an orbital-free picture, a molecule can be regarded as a polynuclear system immersed in a static electron density.
