From 90a16fc541f4a5c685366e94ed568b6a3c02416d Mon Sep 17 00:00:00 2001 From: Emmanuel Fromager Date: Wed, 30 Oct 2019 13:38:08 +0100 Subject: [PATCH] Manu: started polishing the entire theory section --- Manuscript/eDFT.tex | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/Manuscript/eDFT.tex b/Manuscript/eDFT.tex index e960008..7974788 100644 --- a/Manuscript/eDFT.tex +++ b/Manuscript/eDFT.tex @@ -165,20 +165,12 @@ In these extreme conditions, where magnetic effects compete with Coulombic force Atomic units are used throughout. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\section{Density-functional theory for ensembles} +\section{Theory} \label{sec:eDFT} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\subsection{Generalized KS-eDFT} -\label{sec:geKS} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{Kohn--Sham formulation of GOK-DFT} -Since Hartree and exchange energy contributions cannot be separated in -the one-dimensional case, we introduce in the following an alternative -formulation of KS-eDFT where, in complete analogy with the generalized -KS scheme, a HF-like Hartree-exchange energy is employed. This -formulation is in principle exact and applicable to higher dimensions. Let us start from the analog for ensembles of Levy's universal functional, \beq\label{eq:ens_LL_func} @@ -199,7 +191,19 @@ where $\hat{n}(\br)$ is the density operator, $n_{\Psi}$ denotes the density of wavefunction $\Psi$, and $\bw\equiv\left(w^{(1)},w^{(2)},\ldots\right)$ is the collection of (decreasing) ensemble weights assigned to the excited states. Note that -$w_0=1-\sum_{K>0}w_K\geq 0$. When $\bw=0$, the +$w_0=1-\sum_{K>0}w_K\geq 0$. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{Hybrid GOK-DFT} +\label{sec:geKS} +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +Since Hartree and exchange energy contributions cannot be separated in +the one-dimensional case, we introduce in the following an alternative +formulation of KS-eDFT where, in complete analogy with the generalized +KS scheme, a HF-like Hartree-exchange energy is employed. This +formulation is in principle exact and applicable to higher dimensions. + + When $\bw=0$, the conventional ground-state universal functional is recovered, \beq F^{\bw=0}[n]=F[n]=\underset{\Psi\rightarrow n}{\rm min} @@ -528,7 +532,7 @@ Hxc}(n)}{\partial w_K}\right|_{n=n_{\bmg^{\bw}}(\br)}. \eeq } -\subsection{OEP-like approach} +\subsection{Exact ensemble exchange in hybrid GOK-DFT} In the exact theory, the minimizing density matrix in @@ -710,6 +714,12 @@ c}(n)}{\partial w_K}\right|_{n=n_{\bmg^{\bw}}(\br)}. \alert{Secs. \ref{sec:KS-eDFT}-\ref{sec:E_I} should maybe be moved to an appendix or merged with the theory section (?)} + +%%%%%%%%%%%%%%%% +\section{Implementation} + +%%%%%%%%%%%%%%%% + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{KS-eDFT for excited states} \label{sec:KS-eDFT}