diff --git a/Manuscript/FarDFT.tex b/Manuscript/FarDFT.tex index c1292eb..5fbb85c 100644 --- a/Manuscript/FarDFT.tex +++ b/Manuscript/FarDFT.tex @@ -471,20 +471,13 @@ For all calculations, we use the aug-cc-pVXZ (X = D, T, Q, and 5) Dunning family Numerical quadratures are performed with the \texttt{numgrid} library \cite{numgrid} using 194 angular points (Lebedev grid) and a radial precision of $10^{-6}$. \cite{Becke_1988b,Lindh_2001} This study deals only with spin-unpolarised systems, \ie, $\n{\uparrow}{} = \n{\downarrow}{} = \n{}{}/2$ (where $\n{\uparrow}{}$ and $\n{\downarrow}{}$ are the spin-up and spin-down electron densities). Moreover, we restrict our study to the case of a two-state ensemble (\ie, $\nEns = 2$) where both the ground state ($I=0$ with weight $1 - \ew{}$) and the first doubly-excited state ($I=1$ with weight $\ew{}$) are considered. -Although one should have $0 \le \ew{} \le 1/2$ to ensure the GOK variational principle, we will sometimes ``violate'' this variational constraint. +\titou{To ensure the GOK variational principle, one should then have $0 \le \ew{} \le 1/2$. +However, we will sometimes ``violate'' this variational constraint. Indeed, the limit $\ew{} = 1$ is of particular interest as it corresponds to a genuine saddle point of the KS equations, and match perfectly the results obtained with the maximum overlap method (MOM) developed by Gilbert, Gill and coworkers. \cite{Gilbert_2008,Barca_2018a,Barca_2018b} -\manu{I think we need to be a bit more clear about the $\ew{} = 1$ case, as -it stands a little bit beyond the theory discussed previously. What you -are looking at in the range $1/2\leq \ew{}\leq 1$ are, indeed, other -stationary points (than the minimizing ones) of the density matrix -operator functional in Eq.~\eqref{eq:min_KS_DM}. I would say that we -look at these solutions for analysis purposes. I personally never looked -(formally) at these solutions and their physical meaning. One should clearly -mention that applying GOK-DFT in this range of weights would simply -consists in switching ground and first excited states if a true -minimization of the ensemble energy were performed. From this point of -view we do not violate anything. -} +Although the range $1/2 < \ew{} \leq 1$ stands a little bit beyond the theory discussed previously, we look at these solutions for analysis purposes mainly. +These solutions of the density matrix operator functional in Eq.~\eqref{eq:min_KS_DM} correspond to stationary points rather than minimising ones. +Applying GOK-DFT in this range of weights would simply consists in switching the ground and excited states if true minimisations of the ensemble energy were performed.} + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \section{Results}