diff --git a/BSE-PES.tex b/BSE-PES.tex
index e53e424..6ac610f 100644
--- a/BSE-PES.tex
+++ b/BSE-PES.tex
@@ -146,7 +146,7 @@
 \newcommand{\bB}[1]{\mathbf{B}^{#1}}
 \newcommand{\bX}[1]{\mathbf{X}^{#1}}
 \newcommand{\bY}[1]{\mathbf{Y}^{#1}}
-\newcommand{\bZ}[1]{\mathbf{Z}^{#1}}
+\newcommand{\bZ}[2]{\mathbf{Z}_{#1}^{#2}}
 \newcommand{\bK}{\mathbf{K}}
 \newcommand{\bP}[1]{\mathbf{P}^{#1}}
 
@@ -302,14 +302,14 @@ In the following, the index $m$ labels the $\Nocc \Nvir$ single excitations, $i$
 In the absence of instabilities (\ie, when $\bA{\IS} - \bB{\IS}$ is positive-definite), \cite{Dreuw_2005} Eq.~\eqref{eq:LR} is usually transformed into an Hermitian eigenvalue problem of smaller dimension
 \begin{equation}
 \label{eq:small-LR}
-	(\bA{\IS} - \bB{\IS})^{1/2} (\bA{\IS} + \bB{\IS}) (\bA{\IS} - \bB{\IS})^{1/2} \bZ{\IS}_m = (\Om{m}{\IS})^2 \bZ{\IS}_m,
+	(\bA{\IS} - \bB{\IS})^{1/2} (\bA{\IS} + \bB{\IS}) (\bA{\IS} - \bB{\IS})^{1/2} \bZ{m}{\IS} = (\Om{m}{\IS})^2 \bZ{m}{\IS},
 \end{equation}
 where the excitation amplitudes are
 \begin{subequations}
 \begin{align}
-	\bX{\IS} + \bY{\IS} = (\bOm{\IS})^{-1/2} (\bA{\IS} - \bB{\IS})^{+1/2} \bZ{\IS},
+	(\bX{\IS} + \bY{\IS})_m = (\Om{m}{\IS})^{-1/2} (\bA{\IS} - \bB{\IS})^{+1/2} \bZ{m}{\IS},
 	\\
-	\bX{\IS} - \bY{\IS} = (\bOm{\IS})^{+1/2} (\bA{\IS} - \bB{\IS})^{-1/2} \bZ{\IS}.
+	(\bX{\IS} - \bY{\IS})_m = (\Om{m}{\IS})^{+1/2} (\bA{\IS} - \bB{\IS})^{-1/2} \bZ{m}{\IS}.
 \end{align}
 \end{subequations}
 Introducing the so-called Mulliken notation for the bare two-electron integrals
diff --git a/Data/H2_GS_VDZ.pdf b/Data/H2_GS_VDZ.pdf
index ef20f3e..3d6e0fb 100644
Binary files a/Data/H2_GS_VDZ.pdf and b/Data/H2_GS_VDZ.pdf differ