Interaction energy

In physics, interaction energy is the contribution to the total energy that is caused by an interaction between the objects being considered. In physics, interaction energy is the contribution to the total energy that is caused by an interaction between the objects being considered. The interaction energy usually depends on the relative position of the objects. For example, Q 1 Q 2 / ( 4 π ϵ 0 Δ r ) {displaystyle Q_{1}Q_{2}/(4pi epsilon _{0}Delta r)} is the electrostatic interaction energy between two objects with charges Q 1 {displaystyle Q_{1}} , Q 2 {displaystyle Q_{2}} . A straightforward approach for evaluating the interaction energy is to calculate the difference between the energies of isolated objects and their assembly. In the case of two objects, A and B, the interaction energy can be written as: Δ E i n t = E ( A , B ) − ( E ( A ) + E ( B ) ) {displaystyle Delta E_{int}=E(A,B)-left(E(A)+E(B) ight)} , where E ( A ) {displaystyle E(A)} and E ( B ) {displaystyle E(B)} are the energies of the isolated objects (monomers), and E ( A , B ) {displaystyle E(A,B)} the energy of their interacting assembly (dimer). For larger system, consisting of N objects, this procedure can be generalized to provide a total many-body interaction energy: Δ E i n t = E ( A 1 , A 2 , . . , A N ) − ∑ i = 1 N E ( A i ) {displaystyle Delta E_{int}=E(A_{1},A_{2},..,A_{N})-sum _{i=1}^{N}E(A_{i})} .