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[lectures/latex.git] / posic / talks / defense.txt

diff --git a/posic/talks/defense.txt b/posic/talks/defense.txt
index 94350c3..79243cc 100644 (file)
--- a/posic/talks/defense.txt
+++ b/posic/talks/defense.txt
@@ -224,8 +224,9 @@ slide 10
 
 defect structures are obtained by creating a supercell of crystalline silicon
 with periodic boundary conditions and temperature and pressure set to zero.
 
 defect structures are obtained by creating a supercell of crystalline silicon
 with periodic boundary conditions and temperature and pressure set to zero.

-the interstitial carbon or silicon atom is inserted followed by
-structural relaxation into a local minimum configuration.
+the interstitial carbon or silicon atom is inserted,
+for example at the tetrahedral or heexagonal site,
+followed by structural relaxation into a local minimum configuration.

 
 next to the structure, defects can be characterized by formation energies,
 which is defined by this formula, where the chemical potential
 
 next to the structure, defects can be characterized by formation energies,
 which is defined by this formula, where the chemical potential


@@ -247,7 +248,16 @@ each step the configurational energy of the relaxed structure is recorded.
 
 slide 11
 
 
 slide 11
 

-
+in the following, structures and formation energies
+of silicon self-interstitial defects are shown.
+the classical potential and ab initio method predict formation energies,
+which are within the same order of magnitude.
+however, discrepancies exist.
+quantum-mechanical results reveal the silicon 110 interstitial dumbbell (db)
+as the ground state closely followed by the hexagonal and tetrahedral
+configuration, which is the consensus view for silicon interstitials.
+in contrast, the ea potential favors the tetrahedral configuration,
+a known problem, which arises due to the cut-off ...

 
 slide 12
 slide 13
 
 slide 12
 slide 13