\part{Mathematical foundations}
-Reminder: Modern Quantum Chemistry \& Sakurai \& Group Theory \ldots
-
\chapter{Linear algebra}
+Reminder: Modern Quantum Chemistry \& Sakurai \& Group Theory \ldots
+
\section{Vectors and bases}
A vector $\vec{a}$ of an $N$-dimensional vector space (see \ref{math_app:vector_space} for mathematical details) is represented by its components $a_i$ with respect to a set of $N$ basis vectors ${\vec{e}_i}$