+% we need both: Si self-int & C int ground state configuration (for combos)\r
+\r
+Several geometries have been calculated to be stable for individual intrinsic and C related defects in Si.\r
+Fig.~\ref{fig:sep_def} shows the obtained structures while the corresponding energies of formation are summarized and compared to values from literature in table~\ref{table:sep_eof}.\r
+\begin{figure}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Si $\langle 1 1 0 \rangle$ DB}\\\r
+\includegraphics[width=\columnwidth]{si110.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Si hexagonal}\\\r
+\includegraphics[width=\columnwidth]{sihex.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Si tetrahedral}\\\r
+\includegraphics[width=\columnwidth]{sitet.eps}\r
+\end{minipage}\\\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Si $\langle 1 0 0 \rangle$ DB}\\\r
+\includegraphics[width=\columnwidth]{si100.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Vacancy}\\\r
+\includegraphics[width=\columnwidth]{sivac.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{Substitutional}\\\r
+\includegraphics[width=\columnwidth]{csub.eps}\r
+\end{minipage}\\\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{C $\langle 1 0 0 \rangle$ DB}\\\r
+\includegraphics[width=\columnwidth]{c100.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{C $\langle 1 1 0 \rangle$ DB}\\\r
+\includegraphics[width=\columnwidth]{c110.eps}\r
+\end{minipage}\r
+\begin{minipage}[t]{0.32\columnwidth}\r
+\underline{C bond-centered}\\\r
+\includegraphics[width=\columnwidth]{cbc.eps}\r
+\end{minipage}\r
+\caption{Configurations of silicon and carbon point defects in silicon. Silicon and carbon atoms are illustrated by yellow and grey spheres respectively. Blue lines are bonds drawn whenever considered appropriate to ease identifying defect structures for the reader. Dumbbell configurations are abbreviated by DB.}\r
+\label{fig:sep_def}\r
+\end{figure}\r
+\begin{table*}\r
+\begin{ruledtabular}\r
+\begin{tabular}{l c c c c c c c c c}\r
+ & Si $\langle1 1 0\rangle$ DB & Si H & Si T & Si $\langle 1 0 0\rangle$ DB & V & C$_{\text{s}}$ & C $\langle1 0 0\rangle$ DB & C $\langle1 1 0\rangle$ DB & C BC \\\r
+\hline\r
+ This work & 3.39 & 3.42 & 3.77 & 4.41 & 3.63 & 1.95 & 3.72 & 4.16 & 4.66 \\\r
+ References & 3.40\cite{al-mushadani03}, 3.31\cite{leung99} & 3.45\cite{al-mushadani03}, 3.31\cite{leung99} & 3.43\cite{leung99} & - & 3.53\cite{al-mushadani03} & 1.89\cite{dal_pino93} & x & - & x+2.1\cite{capaz94}\r
+\end{tabular}\r
+\end{ruledtabular}\r
+\caption{Formation energies of silicon and carbon point defects in crystalline silicon. The formation energies are given in eV. T denotes the tetrahedral, H the hexagonal and BC the bond-centered interstitial configuration. V corresponds to the vacancy configuration. Dumbbell configurations are abbreviated by DB.}\r
+\label{tab:sep_eof}\r
+\end{table*}\r
+\r
+The ground state configurations of a Si self-interstitial and a C interstitial is the $\langle 1 1 0 \rangle$ and $\langle 1 0 0 \rangle$ dumbbell respectively.\r