+ \section*{Interstitial configurations}
+ {\bf Simulation sequence:}\\
+
+\begin{minipage}{15cm}
+{\small
+ \begin{pspicture}(0,0)(14,14)
+ \rput(7,12.5){\rnode{init}{\psframebox[fillstyle=solid,fillcolor=green]{
+ \parbox{14cm}{
+ \begin{itemize}
+ \item Initial configuration: $9\times9\times9$ unit cells Si
+ \item Periodic boundary conditions
+ \item $T=0\text{ K}$, $p=0\text{ bar}$
+ \end{itemize}
+ }}}}
+\rput(7,6){\rnode{insert}{\psframebox{
+ \parbox{14cm}{
+ Insertion of C / Si atom:
+ \begin{itemize}
+ \item $(0,0,0)$ $\rightarrow$ {\color{red}tetrahedral}
+ (${\color{red}\triangleleft}$)
+ \item $(-1/8,-1/8,1/8)$ $\rightarrow$ {\color{green}hexagonal}
+ (${\color{green}\triangleright}$)
+ \item $(-1/8,-1/8,-1/4)$, $(-3/8,-3/8,-1/4)$\\
+ $\rightarrow$ {\color{magenta}110 dumbbell}
+ (${\color{magenta}\Box}$,$\circ$)
+ \item random positions (critical distance check)
+ \end{itemize}
+ }}}}
+ \rput(7,1.5){\rnode{cool}{\psframebox[fillstyle=solid,fillcolor=cyan]{
+ \parbox{7cm}{
+ Relaxation time: 2 ps
+ }}}}
+ \ncline[]{->}{init}{insert}
+ \ncline[]{->}{insert}{cool}
+ \end{pspicture}
+}
+\end{minipage}
+\begin{minipage}{10cm}
+ \includegraphics[width=11cm]{unit_cell_s.eps}
+\end{minipage}
+
+ {\bf Si self-interstitial results:}\\
+
+{\small
+ \begin{minipage}[t]{8.5cm}
+ \underline{Tetrahedral}\\
+ $E_f=3.41$ eV\\
+ \includegraphics[width=8cm]{si_self_int_tetra_0.eps}
+ \end{minipage}
+ \begin{minipage}[t]{8.5cm}
+ \underline{110 dumbbell}\\
+ $E_f=4.39$ eV\\
+ \includegraphics[width=8cm]{si_self_int_dumbbell_0.eps}
+ \end{minipage}
+ \begin{minipage}[t]{8.5cm}
+ \underline{Hexagonal}\\
+ $E_f^{\star}\approx4.48$ eV (unstable!)\\
+ \includegraphics[width=8cm]{si_self_int_hexa_0.eps}
+ \end{minipage}\\[1cm]
+
+ \underline{Random insertion}\\
+
+ \begin{minipage}{8.5cm}
+ $E_f=3.97$ eV\\
+ \includegraphics[width=8cm]{si_self_int_rand_397_0.eps}
+ \end{minipage}
+ \begin{minipage}{8.5cm}
+ $E_f=3.75$ eV\\
+ \includegraphics[width=8cm]{si_self_int_rand_375_0.eps}
+ \end{minipage}
+ \begin{minipage}{8.5cm}
+ $E_f=3.56$ eV\\
+ \includegraphics[width=8cm]{si_self_int_rand_356_0.eps}
+ \end{minipage}\\[1cm]
+}
+
+ {\bf C in Si interstitial results:}\\
+
+{\small
+ \begin{minipage}[t]{8.5cm}
+ \underline{Tetrahedral}\\
+ $E_f=2.67$ eV\\
+ \includegraphics[width=8cm]{c_in_si_int_tetra_0.eps}
+ \end{minipage}
+ \begin{minipage}[t]{8.5cm}
+ \underline{110 dumbbell}\\
+ $E_f=1.76$ eV\\
+ \includegraphics[width=8cm]{c_in_si_int_dumbbell_0.eps}
+ \end{minipage}
+ \begin{minipage}[t]{8.5cm}
+ \underline{Hexagonal}\\
+ $E_f^{\star}\approx5.6$ eV (unstable!)\\
+ \includegraphics[width=8cm]{c_in_si_int_hexa_0.eps}
+ \end{minipage}\\[1cm]
+}
+\begin{minipage}{17cm}
+\underline{$<100>$ dumbbell configuration}
+\begin{itemize}
+ \item $E_f=0.47$ eV
+ \item Very often observed
+ \item Most energetically favorable configuration
+ \item Experimental evidence [6]
+\end{itemize}
+\end{minipage}
+\begin{minipage}{8cm}
+\includegraphics[width=8cm]{c_in_si_int_001db_0.eps}
+\end{minipage}\\[1cm]
+\begin{center}
+\includegraphics[width=24cm]{100-c-si-db_s.eps}
+\end{center}
+{\tiny
+ [6] G. D. Watkins and K. L. Brower, Phys. Rev. Lett. 36 (1976) 1329.}
+