diff --git a/BSEdyn.tex b/BSEdyn.tex index 1c5f48f..319b866 100644 --- a/BSEdyn.tex +++ b/BSEdyn.tex @@ -442,7 +442,7 @@ In Eq.~\eqref{eq:BSE-final}, \ERI{pq}{rs} = \iint d\br d\br' \, \MO{p}^*(\br) \MO{q}(\br) v(\br -\br') \MO{r}^*(\br') \MO{s}(\br'), \end{equation} are the bare two-electron integrals in the spatial orbital basis $\lbrace \MO{p}(\br{}) \rbrace$, and -\begin{multline} +\begin{multline} \label{eq:wtilde} \widetilde{W}_{ij,ab}(\Om{s}{}) = \frac{ i }{ 2 \pi} \int d\omega \; e^{-i \omega 0^+ } W_{ij,ab}(\omega) \\ @@ -507,8 +507,8 @@ with where the $\e{p}$'s are taken as the HF orbital energies in the case of $G_0W_0$ or as the $GW$ quasiparticle energies in the case of self-consistent schemes such as ev$GW$. The RPA matrices $\bA{\RPA}$ and $\bB{\RPA}$ in Eq.~\eqref{eq:LR-RPA} are of size $\Nocc \Nvir \times \Nocc \Nvir$, where $\Nocc$ and $\Nvir$ are the number of occupied and virtual orbitals (\ie, $\Norb = \Nocc + \Nvir$ is the total number of spatial orbitals), respectively, and $\bX{m}{}$, and $\bY{m}{}$ are (eigen)vectors of length $\Nocc \Nvir$. -Because $\Om{m}{\RPA} > 0$, we have -\begin{multline} +The analysis of the poles of the integrand in Eq.~\eqref{eq:wtilde} yields +\begin{multline} \widetilde{W}_{ij,ab}( \Om{s}{} ) = \ERI{ij}{ab} + 2 \sum_m \sERI{ij}{m} \sERI{ab}{m} \\ @@ -527,8 +527,10 @@ For a closed-shell system in a finite basis, to compute the BSE excitation energ \begin{equation} \label{eq:LR-dyn} \begin{pmatrix} - \bA{}(\Om{s}{}) & \bB{}(\Om{s}{}) \\ - -\bB{}(\titou{-}\Om{s}{}) & -\bA{}(\titou{-}\Om{s}{}) \\ + \bA{}(\Om{s}{}) & \bB{}(\Om{s}{}) + \\ + -\bB{}(\titou{-}\Om{s}{}) & -\bA{}(\titou{-}\Om{s}{}) + \\ \end{pmatrix} \cdot \begin{pmatrix} @@ -577,8 +579,10 @@ Now, let us decompose, using basic perturbation theory, the non-linear eigenprob \\ = \begin{pmatrix} - \bA{(0)} & \bB{(0)} \\ - -\bB{(0)} & -\bA{(0)} \\ + \bA{(0)} & \bB{(0)} + \\ + -\bB{(0)} & -\bA{(0)} + \\ \end{pmatrix} + \begin{pmatrix}