This project focuses on the atomic structure and electronic properties of rare earth and transition metal silicide nanowires formed on Si surfaces. The atomic structure is characterized using scanning tunneling microscopy, grazing incidence x-ray diffraction, and low-energy electron diffraction, also with spot-profile analysis and with intensity-voltage analysis. Angle-resolved photoelectron spectroscopy and scanning tunneling spectroscopy are applied for studying the (local) electronic properties. Two strategies for the selforganized nanowire formation are applied, using anisotropic strain of the grown silicides as well as anisotropic substrates. In the first funding period, the work concentrated on rare earth silicide nanowires on the planar and vicinal Si(001) surfaces as well as on corresponding nanostructures on the Si(111) surface. In the second funding period, the focus will shift to rare earth silicide nanowires on anisotropic and vicinal Si surfaces. In addition, alternative material systems such as transition metal nanowires will be studied. For these novel nanowire systems, the growth conditions will be optimized, in particular to obtain sufficiently thin silicide nanowires with corresponding one-dimensional electronic properties. Then the atomic structure and electronic properties will be studied in detail, also for capped nanowires. Moreover, elemental nanowire systems such as Au on Si(111) and Ge(001) will be studied. In addition, optical studies, transport experiments, and theoretical modeling will be performed in cooperating projects in this research group in order to obtain a throughout understanding of the physical properties of the nanowire systems.