From: hackbard <hackbard@sage.physik.uni-augsburg.de>
Date: Fri, 10 Jul 2009 16:06:32 +0000 (+0200)
Subject: weekend commit :)
X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=308a99aefd361f2e795db24e852574f91758a9df;p=lectures%2Flatex.git

weekend commit :)
---

diff --git a/posic/talks/upb-ua-xc.tex b/posic/talks/upb-ua-xc.tex
index e95c0fb..502375b 100644
--- a/posic/talks/upb-ua-xc.tex
+++ b/posic/talks/upb-ua-xc.tex
@@ -218,7 +218,7 @@ POTIM = 0.1
  \begin{itemize}
   \item Calculation of cohesive energies for different lattice constants
   \item No ionic update
-  \item tetrahedron method with Blöchl corrections for
+  \item Tetrahedron method with Blöchl corrections for
         the partial occupancies $f_{nk}$
   \item Supercell 3 (8 atoms, 4 primitive cells)
  \end{itemize}
@@ -269,7 +269,7 @@ POTIM = 0.1
  \begin{itemize}
   \item Calculation of cohesive energies for different lattice constants
   \item No ionic update
-  \item tetrahedron method with Blöchl corrections for
+  \item Tetrahedron method with Blöchl corrections for
         the partial occupancies $f_{nk}$
  \end{itemize}
  \vspace*{0.6cm}
@@ -379,6 +379,49 @@ POTIM = 0.1
 
 \end{slide}
 
+\begin{slide}
+
+ {\large\bf
+  Used types of supercells\\
+ }
+
+ \footnotesize
+
+ \begin{minipage}{4.3cm}
+  \includegraphics[width=4cm]{sc_type0.eps}\\[0.3cm]
+  \underline{Type 0}\\[0.2cm]
+  Basis: fcc\\
+  $x_1=(0.5,0.5,0)$\\
+  $x_2=(0,0.5,0.5)$\\
+  $x_3=(0.5,0,0.5)$\\
+  1 primitive cell / 2 atoms
+ \end{minipage}
+ \begin{minipage}{4.3cm}
+  \includegraphics[width=4cm]{sc_type1.eps}\\[0.3cm]
+  \underline{Type 1}\\[0.2cm]
+  Basis:\\
+  $x_1=(0.5,-0.5,0)$\\
+  $x_2=(0.5,0.5,0)$\\
+  $x_3=(0,0,1)$\\
+  2 primitive cells / 4 atoms
+ \end{minipage}
+ \begin{minipage}{4.3cm}
+  \includegraphics[width=4cm]{sc_type2.eps}\\[0.3cm]
+  \underline{Type 2}\\[0.2cm]
+  Basis: sc\\
+  $x_1=(1,0,0)$\\
+  $x_2=(0,1,0)$\\
+  $x_3=(0,0,1)$\\
+  4 primitive cells / 8 atoms
+ \end{minipage}\\[0.4cm]
+
+ {\bf\color{blue}
+ In the following these types of supercells are used and
+ are possibly scaled by integers in the different directions!
+ }
+
+\end{slide}
+
 \begin{slide}
 
  {\large\bf
@@ -403,10 +446,52 @@ POTIM = 0.1
                -E_{\textrm{coh}}^{\textrm{initial conf}}\Big) N
  \]
  }
-
- \begin{center}
+ Influence of supercell size\\
+ \begin{minipage}{8cm}
  \includegraphics[width=7.0cm]{si_self_int.ps}
- \end{center}
+ \end{minipage}
+ \begin{minipage}{5cm}
+ $E_{\textrm{f}}^{\textrm{110},\,32\textrm{pc}}=3.38\textrm{ eV}$\\
+ $E_{\textrm{f}}^{\textrm{tet},\,32\textrm{pc}}=3.41\textrm{ eV}$\\
+ $E_{\textrm{f}}^{\textrm{hex},\,32\textrm{pc}}=3.42\textrm{ eV}$\\
+ $E_{\textrm{f}}^{\textrm{vac},\,32\textrm{pc}}=3.51\textrm{ eV}$
+ \end{minipage}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Questions so far ...\\
+ }
+
+ What configuration to chose for C in Si simulations?
+ \begin{itemize}
+  \item Switch to another method for the XC approximation (GGA, PAW)?
+  \item Reasonable cut-off energy
+  \item Switch off symmetry? (especially for defect simulations)
+  \item $k$-points
+        (Monkhorst? $\Gamma$-point only if cell is large enough?)
+  \item Switch to tetrahedron method or Gaussian smearing ($\sigma$?)
+  \item Size and type of supercell
+        \begin{itemize}
+         \item connected to choice of $k$-point mesh?
+         \item hence also connected to choice of smearing method?
+         \item constraints can only be applied to the lattice vectors!
+        \end{itemize}
+  \item \ldots
+ \end{itemize}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Review (so far) ...\\
+ }
+
+ 
+ 
 
 \end{slide}