+\begin{figure}[tp]
+\begin{center}
+\includegraphics[width=0.7\textwidth]{bc_00-1_albe_s.ps}
+%\includegraphics[width=13cm]{bc_00-1.ps}\\[5.6cm]
+%\begin{pspicture}(0,0)(0,0)
+%\psframe[linecolor=red,fillstyle=none](-7,2.7)(7.2,6)
+%\end{pspicture}
+%\begin{picture}(0,0)(140,-100)
+%\includegraphics[width=2.4cm]{albe_mig/bc_00-1_red_00.eps}
+%\end{picture}
+%\begin{picture}(0,0)(10,-100)
+%\includegraphics[width=2.4cm]{albe_mig/bc_00-1_red_01.eps}
+%\end{picture}
+%\begin{picture}(0,0)(-120,-100)
+%\includegraphics[width=2.4cm]{albe_mig/bc_00-1_red_02.eps}
+%\end{picture}
+%\begin{picture}(0,0)(25,-80)
+%\includegraphics[width=2.5cm]{110_arrow.eps}
+%\end{picture}
+%\begin{picture}(0,0)(215,-100)
+%\includegraphics[height=2.2cm]{001_arrow.eps}
+%\end{picture}\\
+%\begin{pspicture}(0,0)(0,0)
+%\psframe[linecolor=blue,fillstyle=none](-7,-0.5)(7.2,2.8)
+%\end{pspicture}
+%\begin{picture}(0,0)(160,-10)
+%\includegraphics[width=2.2cm]{albe_mig/bc_00-1_01.eps}
+%\end{picture}
+%\begin{picture}(0,0)(100,-10)
+%\includegraphics[width=2.2cm]{albe_mig/bc_00-1_02.eps}
+%\end{picture}
+%\begin{picture}(0,0)(10,-10)
+%\includegraphics[width=2.2cm]{albe_mig/bc_00-1_03.eps}
+%\end{picture}
+%\begin{picture}(0,0)(-120,-10)
+%\includegraphics[width=2.2cm]{albe_mig/bc_00-1_04.eps}
+%\end{picture}
+%\begin{picture}(0,0)(25,10)
+%\includegraphics[width=2.5cm]{100_arrow.eps}
+%\end{picture}
+%\begin{picture}(0,0)(215,-10)
+%\includegraphics[height=2.2cm]{010_arrow.eps}
+%\end{picture}
+\end{center}
+\caption[Migration barrier and structures of the \ci{} BC to \hkl<0 0 -1> DB transition using the classical EA potential.]{Migration barrier and structures of the \ci{} BC to \hkl[0 0 -1] DB transition using the classical EA potential. Two migration pathways are obtained for different time constants of the Berendsen thermostat. The lowest activation energy is \unit[2.2]{eV}.}
+\label{fig:defects:cp_bc_00-1_mig}
+% red: ./visualize -w 640 -h 480 -d saves/c_in_si_mig_bc_00-1_s20 -nll -0.56 -0.56 -0.7 -fur 0.2 0.2 0.0 -c 0.75 -1.25 -0.25 -L -0.25 -0.25 -0.25 -r 0.6 -B 0.1
+% blue: ./visualize -w 640 -h 480 -d saves/c_in_si_mig_bc_00-1_s20_tr100/ -nll -0.56 -0.56 -0.7 -fur 0.2 0.2 0.0 -c 0.0 -0.25 1.0 -L 0.0 -0.25 -0.25 -r 0.6 -B 0.1
+\end{figure}
+Fig. \ref{fig:defects:cp_bc_00-1_mig} shows the evolution of structure and energy along the \ci{} BC to \hkl<0 0 -1> DB transition.
+Since the \ci{} BC configuration is unstable relaxing into the \hkl<1 1 0> DB configuration within this potential, the low kinetic energy state is used as a starting configuration.
+Two different pathways are obtained for different time constants of the Berendse
+n thermostat.
+With a time constant of \unit[1]{fs} the C atom resides in the \hkl(1 1 0) plane
+ resulting in a migration barrier of \unit[2.4]{eV}.
+However, weaker coupling to the heat bath realized by an increase of the time constant to \unit[100]{fs} enables the C atom to move out of the \hkl(1 1 0) plane already at the beginning, which is accompanied by a reduction in energy, approaching the final configuration on a curved path.
+The energy barrier of this path is \unit[0.2]{eV} lower in energy than the direct migration within the \hkl(1 1 0) plane.
+However, the investigated pathways cover an activation energy approximately twice as high as the one obtained by quantum-mechanical calculations.
+If the entire transition of the \hkl<0 0 -1> into the \hkl<0 0 1> configuration is considered a two step process passing the intermediate BC configuration, an additional activation energy of \unit[0.5]{eV} is necessary to escape the BC towards the \hkl<0 0 1> configuration.
+Assuming equal preexponential factors for both diffusion steps, the total probability of diffusion is given by $\exp\left((2.2\,\text{eV}+0.5\,\text{eV})/k_{\text{B}}T\right)$.
+Thus, the activation energy should be located within the range of \unit[2.2-2.7]{eV}.
+
+\begin{figure}[tp]
+\begin{center}
+\includegraphics[width=0.7\textwidth]{00-1_0-10_albe_s.ps}
+\end{center}
+\caption{Migration barrier and structures of the \ci{} \hkl<0 0 -1> to \hkl<0 -1 0> DB transition using the classical EA potential.}
+% red: ./visualize -w 640 -h 480 -d saves/c_in_si_mig_00-1_0-10_s20 -nll -0.56 -0.56 -0.8 -fur 0.3 0.2 0 -c -0.125 -1.7 0.7 -L -0.125 -0.25 -0.25 -r 0.6 -B 0.1
+\label{fig:defects:cp_00-1_0-10_mig}
+\end{figure}
+\begin{figure}[tp]
+\begin{center}
+\includegraphics[width=0.7\textwidth]{00-1_ip0-10.ps}
+\end{center}
+\caption{Reorientation barrier of the \ci{} \hkl<0 0 -1> to \hkl<0 -1 0> DB transition in place using the classical EA potential.}
+\label{fig:defects:cp_00-1_ip0-10_mig}
+\end{figure}
+Figures \ref{fig:defects:cp_00-1_0-10_mig} and \ref{fig:defects:cp_00-1_ip0-10_mig} show the migration barriers of the \ci{} \hkl<0 0 -1> to \hkl<0 -1 0> DB transition.
+In the first case, the transition involves a change in the lattice site of the C atom whereas in the second case, a reorientation at the same lattice site takes place.
+In the first case, the pathways for the two different time cosntants look similar.
+A local minimum exists in between two peaks of the graph.
+The corresponding configuration, which is illustrated for the results obtained for a time constant of \unit[1]{fs}, looks similar to the \ci{} \hkl<1 1 0> configuration.
+Indeed, this configuration is obtained by relaxation simulations without constraints of configurations near the minimum.
+Activation energies of roughly \unit[2.8]{eV} and \unit[2.7]{eV} are needed for migration.
+
+The \ci{} \hkl<1 1 0> configuration seems to play a decisive role in all migration pathways in the classical potential calculations.
+As mentioned above, the starting configuration of the first migration path, i.e. the BC configuration, is fixed to be a transition point but in fact is unstable.
+Further relaxation of the BC configuration results in the \ci{} \hkl<1 1 0> configuration.
+Even the last two pathways show configurations almost identical to the \ci{} \hkl<1 1 0> configuration, which constitute local minima within the pathways.
+Thus, migration pathways involving the \ci{} \hkl<1 1 0> DB configuration as a starting or final configuration are further investigated.
+\begin{figure}[tp]