Abstract: The ionic bonding molecular internal potential energy functions are analyzed from viewpoint of geometry and physics, the four kinds of molecular bond contributions are compered. This overcomes the lack of consideration of the Madelung potential. The polarization potential and the Fan De-hua potential and then a more comprehensive application of ion precise interaction energy functions are obtained. The energy representation of Madelung potential is also introduced by comparative method and the Kramer formula is obtained. The Schrodinger equation is solved and the analytical solution of energy level is obtained. The Nacl state energy and its based transition frequency are calculated, and the results are in good agreement with experimental values.

Key words: ionic bond molecules, RittneR potential function, F-H theorem, Madelung potential of energy representation, Kramer formula.