The net potential energy between two adjacent ions, Eₙ, may be represented by the sum of Equations 2.9 and 2.11; that is, Eₙ = - A/r + B/rn Calculate the bonding energy E₀ terms of the parameters A, B, and n using the following procedure:

Differentiate Eₙ with respect to r, and then set the resulting expression equal to zero, because the curve of Eₙ versus r is a minimum at E₀.