A method is devised to find a lower bound on the loss function of graphite in the oxygen high energy range where that function is expected to assume constant value. It requires obtaining a small ensemble of classical trajectories of oxygen on graphite and making static measurements of an oxygen on ethylene potential energy surface. An oxygen atom is assumed to be bonded to the graphite surface by diabatic curve crossing from its initial repulsive potential. Subsequently, it is assumed to be ejected as part of a carbon monoxide molecule due to surface impact of another incident oxygen atom. A dynamical calculation is suggested to improve on the approximate method of this work. Once an excited state cross channel coupling constant is known, the ratio of the loss function of that excited state to the loss function of the ground state may be estimated at asymptotic oxygen energies.