Surface reconstruction (a) (b tap Diagram of the Si(111)7x7reconstruction on Si(111)from the work of Brommer et al. Large solid circles denote adatoms.The size of the circle indicates the distance of the atoms from the top of the surface.The(7x7)unit cell is outlinedSurface reconstruction Diagram of the Si(111)-7×7 reconstruction on Si(111) from the work of Brommer et al. Large solid circles denote adatoms. The size of the circle indicates the distance of the atoms from the top of the surface. The (7×7) unit cell is outlined