Interatomic Potential
Index
The interatomic potential describes the interaction between a pair of atoms or the interaction of an atom with a group of atoms in a condensed phase. The potential must have both an attractive and a repulsive component if binding is to occur. The form of the potential energy as a function of lattice spacing (interatomic distance, r) in a solid is illustrated. Each atom in the ideal crystalline solid experiences the same potential due to the other atoms in the material.

The binding energy of the atom in the solid is the depth of the potential well at its minimum. The location of this minimum determines the nearest neighbor distance, r0 , for atoms in the solid.


 
 

From: Barrett, Nix and Tetelman, "The Principles of Engineering Materials," Prentice Hall (1973)
In this potential, individual atoms will vibrate about the position r0 with the amplitude of their vibration being determined by their total energy. Bound atoms will have a negative total energy and the turning points of their motion occur when their potential energy is equal to the total energy.