The electronic structure of a semiconductor surface is studied for the first time using self-consistent nonlocal (first-principles) pseudopotentials. In agreement with the recent local pseudopotential as well as tight-binding studies, no intrinsic surface states are obtained in the gap of GaAs for the relaxed surface. However, in contrast with the previous approaches, new features of the electronic structure are obtained, including a pronounced downwards displacement of the low As-derived surface states, the appearance of an additional As $p$ state near the valence-band maximum, the reordering of the states near ${\overline{X}}^{\prime }$ with a different order of wave-function parity, and the development of pronounced $d$-orbital character (in addition to $s$ and $p$) in the highest occupied and lowest empty surface states.

• Received 26 December 1979

DOI:https://doi.org/10.1103/PhysRevB.22.959