Morse potential V(r) = D_e(1 - e^{-a(r-r_e)})² (canonical anharmonic diatomic)

Morse potential (Morse 1929): the closed-form anharmonic model for the diatomic-molecule bond. Parameters: equilibrium bond length r_e, well depth D_e (dissociation energy), stiffness a = ω_e √(μ/2D_e) (connects curvature to vibrational…