starting with migration experiments now

diff --git a/posic/thesis/defects.tex b/posic/thesis/defects.tex
index afaaf80..3d41711 100644 (file)
--- a/posic/thesis/defects.tex
+++ b/posic/thesis/defects.tex
@@ -452,19 +452,30 @@ This is in agreement with results of the Erhard/Albe potential simulations which
 However, this fact could not be reproduced by spin polarized VASP calculations performed in this work.
 Present results suggest this configuration to be a real local minimum.
 In fact, an additional barrier has to be passed to reach this configuration starting from the \hkl<1 0 0> interstitital configuration, which is investigated in section \ref{subsection:100mig}.
-The carbon atom has been displaced along the axes ... relaxation back ... indicating a real local minimum.
+After slightly displacing the carbon atom along the \hkl<1 0 0> (equivalent to a displacement along \hkl<0 1 0>), \hkl<0 0 1> and \hkl<1 -1 0> direction the resulting structures relax back into the bond-centered configuration.
+As we will see in later migration simulations the same would happen to structures where the carbon atom is displaced along the migration direction, which approximately is the \hkl<1 1 0> direction.
+These relaxations indicate that the bond-cenetered configuration is a real local minimum instead of an assumed saddle point configuration.
 Figure \ref{img:defects:bc_conf} shows the structure, the charge density isosurface and the Kohn-Sham levels of the bond-centered configuration.
 The linear bonds of the carbon atom to the two silicon atoms indicate the $sp$ hybridization of the carbon atom.
 Two electrons participate to the linear $\sigma$ bonds with the silicon neighbours.
 The other two electrons constitute the $2p^2$ orbitals resulting in a net magnetization.
 This is supported by the charge density isosurface and the Kohn-Sham levels in figure \ref{img:defects:bc_conf}.
-The blue torus, reinforcing the assumption of the p orbital, illsutrates the resulting spin up electron density.
+The blue torus, reinforcing the assumption of the p orbital, illustrates the resulting spin up electron density.
 In addition, the energy level diagram shows a net amount of two spin up electrons.
 
 \section[Migration of the carbon \hkl<1 0 0> interstitial]{\boldmath Migration of the carbon \hkl<1 0 0> interstitial}
 \label{subsection:100mig}
 
 In the following the problem of interstitial carbon migration in silicon is considered.
+Since the carbon \hkl<1 0 0> dumbbell interstitial is the most probable hence most important configuration the migration simulations focus on this defect.
+
+There are different methods of computing migration paths and energies.
+Methods and shortcomings.
+
+Three different migration paths are accounted in this work.
+In the first path the carbon atom 
+
+Results and comparison with diffusion experiments.
 
 \section{Combination of point defects}