diff --git a/BSE-PES.tex b/BSE-PES.tex index 1a518ac..38b8f03 100644 --- a/BSE-PES.tex +++ b/BSE-PES.tex @@ -337,6 +337,7 @@ with $\epsilon_{\lambda}$ the dielectric function at coupling constant $\lambda$ \\ \times \qty(\frac{1}{\omega - \OmRPA{m}{\IS} + i \eta} - \frac{1}{\omega + \OmRPA{m}{\IS} - i \eta}), \end{multline} + where the spectral weights at coupling strength $\lambda$ read \begin{equation} \sERI{pq}{m} = \sum_i^{\Nocc} \sum_a^{\Nvir} \ERI{pq}{ia} (\bX{\IS}_m + \bY{\IS}_m)_{ia}. @@ -344,6 +345,7 @@ where the spectral weights at coupling strength $\lambda$ read In Eq.~\eqref{eq:W}, $\eta$ is a positive infinitesimal, and $\OmRPA{m}{\IS}$ are the direct (\ie, without exchange) RPA neutral excitation energies computed by solving the linear eigenvalue problem \eqref{eq:LR} with the following matrix elements \begin{subequations} +\label{eq:LR_RPA} \begin{align} \label{eq:LR_RPA} \ARPA{ia,jb}{\IS} & = \delta_{ij} \delta_{ab} (\eHF{a} - \eHF{i}) + 2 \IS \ERI{ia}{jb}, @@ -357,6 +359,7 @@ The relation between the BSE formalism and the well-known RPAx approach can be o %namely setting $\epsilon_{\lambda}({\bf r},{\bf r}'; \omega) = \delta({\bf r}-{\bf r}')$ so that $W^{\lambda}$ reduces to the bare Coulomb potential. In that limit, the $GW$ quasiparticle energies reduce to the Hartree-Fock eigenvalues, and Eqs.~\ref{eq:LR_BSE} to the RPAx equations: \begin{subequations} +\label{eq:LR_RPAx} \begin{align} \label{eq:LR_RPAx} \ARPAx{ia,jb}{\IS} & = \delta_{ij} \delta_{ab} (\eHF{a} - \eHF{i}) + \IS \qty[ 2 \ERI{ia}{jb} - \ERI{ij}{ab} ],