diff --git a/Manuscript/SRGGW.tex b/Manuscript/SRGGW.tex index 24464e0..eb6be34 100644 --- a/Manuscript/SRGGW.tex +++ b/Manuscript/SRGGW.tex @@ -248,7 +248,7 @@ Various choices for $\bSig^{\qsGW}$ are possible but the most popular is the fol \label{eq:sym_qsgw} \Sigma_{pq}^{\qsGW} = \frac{1}{2}\Re[\Sigma_{pq}(\epsilon_p) + \Sigma_{pq}(\epsilon_q) ], \end{equation} -which was first introduced by Faleev and co-workers \cite{Faleev_2004,vanSchilfgaarde_2006,Kotani_2007} before being derived as the effective Hamiltonian that minimizes the length of the gradient of the Klein functional for non-interacting Green's functions by Ismail-Beigi. \cite{Ismail-Beigi_2017} +which was first introduced by Faleev and co-workers \cite{Faleev_2004,vanSchilfgaarde_2006,Kotani_2007} before being derived by Ismail-Beigi as the effective Hamiltonian that minimizes the length of the gradient of the Klein functional for non-interacting Green's functions. \cite{Ismail-Beigi_2017} The corresponding matrix elements are \begin{equation} \label{eq:sym_qsGW} @@ -257,7 +257,7 @@ The corresponding matrix elements are + \eta^2} +\frac{\Delta_{qr}^{\nu}}{(\Delta_{qr}^{\nu})^2 + \eta^2} ] W_ {pr}^{\nu} W_{qr}^{\nu}, \end{equation} with $\Delta_{pr}^{\nu} = \epsilon_p - \epsilon_r - \sgn(\epsilon_r-\epsilon_F)\Omega_\nu$ (where $\epsilon_F$ is the energy of the Fermi level). -One of the main results of the present manuscript is the derivation, from first principles, of an alternative static Hermitian form for the $GW$ self-energy. +One of the main results of the present manuscript is the derivation, from first principles, of an alternative static Hermitian form for the qs$GW$ self-energy. Once again, in cases where multiple solutions have large spectral weights, self-consistency can be difficult to reach at the qs$GW$ level. Multiple solutions of Eq.~\eqref{eq:G0W0} arise due to the $\omega$ dependence of the self-energy. @@ -290,7 +290,8 @@ This transformation can be performed continuously via a unitary matrix $\bU(s)$, \label{eq:SRG_Ham} \bH(s) = \bU(s) \, \bH \, \bU^\dag(s), \end{equation} -where the flow parameter $s$ controls the extent of the decoupling and is related to an energy cutoff $\Lambda=s^{-1/2}$ that avoids states with energy denominators smaller than $\Lambda$ to be decoupled from the reference space, hence avoiding potential intruders. +\ant{where the flow parameter $s$ controls the extent of the decoupling and is related to an energy cutoff $\Lambda=s^{-1/2}$. +For a given value of $s$, only states with energy denominators smaller than $1/\Lambda$ will be decoupled from the reference space, hence avoiding potential intruders.} By definition, the boundary conditions are $\bH(s=0) = \bH$ [or $\bU(s=0) = \bI$] and $\bH^\text{od}(s=\infty) = \bO$. An evolution equation for $\bH(s)$ can be easily obtained by differentiating Eq.~\eqref{eq:SRG_Ham} with respect to $s$, yielding the flow equation @@ -308,7 +309,7 @@ In this work, we consider Wegner's canonical generator \cite{Wegner_1994} \begin{equation} \boldsymbol{\eta}^\text{W}(s) = \comm{\bH^\text{d}(s)}{\bH(s)} = \comm{\bH^\text{d}(s)}{\bH^\text{od}(s)}, \end{equation} -which satisfied the following condition \cite{Kehrein_2006} +which satisfies the following condition \cite{Kehrein_2006} \begin{equation} \label{eq:derivative_trace} \dv{s}\text{Tr}\left[ \bH^\text{od}(s)^2 \right] \leq 0.