First-Principles Studies of the Electronic and Vibrational Properties of \textit{sila-}Diamondoids

Diamondoids are cage-like, stable, saturated hydrocarbons, which possess a~rigid carbon-framework that is superimposable upon the diamond crystal structure. These carbon-based diamondoids could be important building blocks in a variety of applications in biochemistry and nanotechnology. While the chemistry of silicon is not as robust as that of carbon, silicon-based analogues of diamondoids such as \textit{sila}-adamantane (Si$_{10}$H$_{16})$ do exist and there is reason to believe that larger sila-diamondoids might either be synthesized in the lab one day or observed experimentally in chemical vapor deposition (CVD) experiments. In this work we show that density-functional theory (DFT) can accurately compute the electronic, structural, and vibrational properties of a variety of lower and medium-order \textit{sila-}diamondoids. We believe that DFT is an important tool that will assist experimentalists in identifying more complicated \textit{sila}-diamondoids that either may be synthesized or already may exist as important intermediates in CVD experiments to grow silicon surfaces.