2x1 reconstructed Si(111) surface: STM experiments versus ab initio calculations

The electronic structure of the Si(111)-2x1 surface has been studied with scanning tunneling spectroscopy (STS). A large experimental local density of states data set of LDOS(x,y,E) with subatomic resolution has been compared with ab initio calculated LDOS distributions. The influence of the tunneling tip DOS has been eliminated by repeated measurements with different tips. The experimentally determined shape of the LDOS(x,y,E) agrees very well with the calculated results based on the pi-bonded-chain model for both the surface valence and the conduction band. The good agreement with ab initio calculations of the electronic structure of the Si(111)-2x1 surface shows that STS provides reliable information of the sample LDOS even with subatomic resolution.