  This paper reports state-of-the-art electronic structure calculations on the
deposition of strontium on the technologically relevant, (001) orientated
silicon surface. We identified the surface reconstructions from zero to four
thirds monolayers and relate them to experimentally reported data. A phase
diagram is proposed. We predict phases at 1/6, 1/4, 1/2, 2/3 and 1 monolayers.
Our results are expected to provide valuable information in order to understand
heteroepitaxial growth of a prominent class of high-K oxides around SrTiO3. The
insight obtained for strontium is expected to be transferable to other alkaline
earth metals.
