Desorption induced by single and multiple electronic transitions is described by a reduced density matrix formulation in a discrete energy representation. The discrete energy basis is comprised of the eigenfunctions of the system Hamiltonian augmented by an asymptotic potential wall, and has a number of advantages over its coordinate counterpart, such as the minimization of the basis size. The Liouville-von Neumann equation of a Lindblad semigroup form is solved numerically using a short-time Chebyshev propagation scheme. The dynamics of NO photodesorption from metals is investigated with one-dimensional two-state models corresponding to both the Menzel-Gormer-Redhead and Antoniewicz mechanisms. Desorption stimulated by both weak cw and strong pulsed light sources are examined.