+Figure \ref{fig:defects:comb_db_01} shows the structure of these two configurations.
+The displayed configurations are realized by creating a \hkl<1 0 0> (a)) and \hkl<0 -1 0> (b)) dumbbell at position 1.
+Structure \ref{fig:defects:comb_db_01} b) is the energetically most favorable configuration.
+After relaxation the initial configuration is still evident.
+As expected by the initialization conditions the two carbon atoms form a bond.
+This bond has a length of 1.38 \AA{} close to the nex neighbour distance in diamond or graphite, which is approximately 1.54 \AA.
+The minimum of binding energy observed for this configuration suggests prefered C clustering as a competing mechnism to the C-Si dumbbell interstitial agglomeration inevitable for the SiC precipitation.
+Todo: Activation energy to obtain a configuration of separated C atoms again or vice versa to obtain this configuration from separated C confs?
+However, for the second most favorable configuration, presented in figure \ref{fig:defects:comb_db_01} a), the amount of possibilities for this configuration is twice as high.
+In this configuration the initial Si (I) and C (I) dumbbell atoms are displaced along \hkl<1 0 0> and \hkl<-1 0 0> in such a way that the Si atom is forming tetrahedral bonds with two silicon and two carbon atoms.
+The carbon and silicon atom constituting the second defect are as well displaced in such a way, that the carbon atom forms tetrahedral bonds with four silicon neighbours, a configuration expected in silicon carbide.
+The two carbon atoms spaced by 2.70 \AA{} do not form a bond but anyhow reside in a shorter distance as expected in silicon carbide.
+The Si atom numbered 2 is pushed towards the carbon atom, which results in the breaking of the bond to atom 4.
+The breaking of the $\sigma$ bond is indeed confirmed by investigating the charge density isosurface of this configuration.
+Todo: Is this conf really benificial for SiC prec?
+
+\begin{figure}[h]
+\begin{center}
+\begin{minipage}[t]{5cm}
+a) \underline{$E_{\text{b}}=-2.16\text{ eV}$}
+\begin{center}
+\includegraphics[width=4.8cm]{00-1dc/2-16.eps}
+\end{center}
+\end{minipage}
+\begin{minipage}[t]{5cm}
+b) \underline{$E_{\text{b}}=-1.90\text{ eV}$}
+\begin{center}
+\includegraphics[width=4.8cm]{00-1dc/1-90.eps}
+\end{center}
+\end{minipage}
+\begin{minipage}[t]{5cm}
+c) \underline{$E_{\text{b}}=-2.05\text{ eV}$}
+\begin{center}
+\includegraphics[width=4.8cm]{00-1dc/2-05.eps}
+\end{center}
+\end{minipage}
+\end{center}
+\caption{Relaxed structures of defect complexes obtained by creating a a) \hkl<1 0 0> and b) \hkl<0 1 0> dumbbell at position 2 and a c) \hkl<0 0 1> dumbbel at position 3.}
+\label{fig:defects:comb_db_02}
+\end{figure}
+Figure \ref{fig:defects:comb_db_02} shows the next three most energetically favorable configurations.
+The relaxed configuration obtained by creating a second \hkl<1 0 0> dumbbell at position 2 is shown in figure \ref{fig:defects:comb_db_02} a).
+A binding energy of -2.16 eV is observed.
+After relaxation the second dumbbell is aligned along \hkl<1 1 0>.
+The bond of the silicon atoms 1 and 2 does not persist.
+Instead the silicon atom forms a bond with the initial carbon interstitial and the second carbon atom forms a bond with silicon atom 1 forming four bonds in total.
+The carbon atoms are spaced by 3.14 \AA, which is very close to the expected C-C next neighbour distance of 3.08 \AA{} in silicon carbide.
+
+
+-2.05 ... both C atoms correctly coordinated, however (check C-C distance, too close?) wrong coordination of the C-Si-C bonds which reside in a plane ... all the 4 participating atoms reside in a plane ...
+
+-1.90 ... again, one C atom bound to 4 Si atoms but the second one only bond to three Si atoms. However, C-C slighlty higher.