A quantum yield model developed for use in the near ultraviolet was extended to cover absorption by core-electrons. The model is based on integrating the density-of-states average number of electron-hole pairs created by a primary electron or hole over the distribution of electron-hole pairs created by absorption of photons of energy hv. For core-electron absorption and for photon energies well above the fundamental absorption edge, simple models exist for the results of the integration. These models were used to calculate the photon pair-creation energy W(hv, 300 K) in the vicinity of the silicon L I I , I I I absorption edge. They predict some features superimposed on a small average increase in pair creation energy across the L I I , I I I edge.