We calculate the total energies, geometries and electronic structure for two competing models of the silicon-rich (3 x 2) reconstruction of the P-SiC(001) surface. In order to compare the energies, some value of the chemical potential of silicon atoms must be assumed. For most reasonable assumptions, we find that the Yan-Semond (YS) model is favoured. This model also gives a highest occupied surface state whose dispersion characteristics match photoemission experiments.