From: hackbard Date: Wed, 11 May 2011 17:24:31 +0000 (+0200) Subject: only small changes, speed up with dft! X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7340b277821e2725d1f47f7d1cf230a7a1b0a943;p=lectures%2Flatex.git only small changes, speed up with dft! --- diff --git a/bibdb/bibdb.bib b/bibdb/bibdb.bib index e21d322..4b5e845 100644 --- a/bibdb/bibdb.bib +++ b/bibdb/bibdb.bib @@ -2888,6 +2888,20 @@ notes = "dft, exchange and correlation", } +@Article{kohn99, + title = {Nobel Lecture: Electronic structure of matter---wave functions and density functionals}, + author = {Kohn, W. }, + journal = {Rev. Mod. Phys.}, + volume = {71}, + number = {5}, + pages = {1253--1266}, + numpages = {13}, + year = {1999}, + month = {Oct}, + doi = {10.1103/RevModPhys.71.1253}, + publisher = {American Physical Society} +} + @Article{ruecker94, title = "Strain-stabilized highly concentrated pseudomorphic $Si1-x$$Cx$ layers in Si", diff --git a/posic/thesis/basics.tex b/posic/thesis/basics.tex index b1beb7f..8ab5002 100644 --- a/posic/thesis/basics.tex +++ b/posic/thesis/basics.tex @@ -277,18 +277,16 @@ It provides a stable algorithm that allows smooth changes of the system to new v \section{Denstiy functional theory} \label{section:dft} -In quantum-mechanical modeling the problem of describing a many-body problem is manifested in the high-dimensional Schr\"odinger equation for the wave function $\Psi({\vec{R}},{\vec{r}})$ that depends on the coordinates of the nuclei and electrons. +In quantum-mechanical modeling the problem of describing the many-body problem, i.e. a system of a large amount of interacting particles, is manifested in the high-dimensional Schr\"odinger equation for the wave function $\Psi({\vec{R}},{\vec{r}})$ that depends on the coordinates of all nuclei and electrons. The Schr\"odinger equation contains the kinetic energy of the ions and electrons as well as the electron-ion, ion-ion and electron-electron interaction. This cannot be solved exactly and there are several layers of approximations to reduce the number of parameters. -In density functional theory (DFT) the problem is recasted to the charge density $n(\vec{r})$ instead of using the description by a wave function. +The key point in density functional theory (DFT) is to recast the problem to a description using the charge density $n(\vec{r})$ that depends on only three spatial coordinates instead of the many-body wave function. Formally DFT can be regarded as an exactification of both, the Thomas Fermi and Hartree theory. - -Since {\textsc vasp} \cite{kresse96} is used in this work, theory and implementation of sophisticated algorithms of DFT codes is not subject of this work. -Thus, the content of the following sections is restricted to the very basic idea of DFT. +In the following sections the basic idea of DFT will be outlined. \subsection{Born-Oppenheimer approximation} -The first approximation ... +The first approximation employed \subsection{Hohenberg-Kohn theorem}