the complex admittance of an n-type hg//1// $minus$ //xcd//xte/photox sio//2 interface with x $equals$ 0. 3 has been examined for frequencies ranging between 1 mhz and 4 mhz. the conductance method is used to decompose the total interface state density into three types of components: a valence-band tail, a conduction-band tail, and some well-resolved discrete states. the fixed charge density is low and there is no statistical broadening the surface valence- and conduction-band edges are both found to be shifted upward in energy relative to their respective bulk values; moreover, the surface has converted to p type. the energy variation of the valence-band tail states response times follows a pattern characteristic of shockley-read recombination centers with a constant capture cross section, but the behavior of the conduction-band tail states is more complicated. evidence is presented that the interface region has a higher cd concentration than the bulk. 16 refs