Photoionization models of NGC 346

We present spherically symmetric and plane-parallel photoionization models of NGC 346, an H II region in the Small Magellanic Cloud. The models are based on CLOUDY and on the observations of Peimbert, Peimbert, & Ruiz. We find that approximately 45% of the H ionization photons escape from the H II region, providing an important ionizing source for the low-density interstellar medium of the SMC. The predicted I(4363)/I(5007) value is smaller than that observed, probably implying that there is an additional source of energy not taken into account by the models. From the ionization structure of the best model and the observed line intensities we determine the abundances of N, Ne, S, Ar, and Fe relative to O.