The defect structures and the migration paths are modelled in cubic supercells containing 216 Si atoms.\r
The ions and cell shape are allowed to change in order to realize a constant pressure simulation.\r
Spin polarization is fully accounted for.\r
+Only neutral defects are considered.\r
\r
% ------ Albe potential ---------\r
%% Frank: Setup/short description of the potential ?\r
Table~\ref{tab:defects} summarizes the formation energies of the interstitial configurations for the Erhart/Albe and VASP calculations performed in this work as well as further results from literature.\r
The formation energies are defined in the same way as in the articles used for comparison\cite{tersoff90,dal_pino93} chosing SiC as a reservoir for the carbon impurity.\r
Relaxed geometries are displayed in Fig.~\ref{fig:defects}.\r
+Astonishingly there is only little literature present to compare with.\r
\begin{table}[th]\r
\begin{tabular}{l c c c c c c}\r
\hline\r
& T & H & \hkl<1 0 0> DB & \hkl<1 1 0> DB & S & B \\\r
\hline\r
Erhart/Albe & 6.09 & 9.05$^*$ & 3.88 & 5.18 & 0.75 & 5.59$^*$ \\\r
- %VASP & unstable & unstable & 3.15 & 3.60 & 1.39 & 4.10 \\\r
VASP & unstable & unstable & 3.72 & 4.16 & 1.95 & 4.66 \\\r
Tersoff\cite{tersoff90} & 3.8 & 6.7 & 4.6 & 5.9 & 1.6 & 5.3 \\\r
ab initio & - & - & x & - & 1.89 \cite{dal_pino93} & x+2.1 \cite{capaz94} \\\r
- more! & - & & & & & \\\r
+ % there is no more data!\r
\hline\r
\hline\r
\end{tabular}\r
\label{fig:defects}\r
\end{figure} \r
\r
-However, there are some discrepancies between the results from classical potential calculations and those obtained from first principles.\r
+Discrepancies are observed between the results from classical potential calculations and those obtained from first principles.\r
\r
While the Erhart/Albe potential predicts ... as stable, DFT does not. ...(further comparisons, trend "too high/low" E-formation,...)... \r
\r