  Twisted bilayer graphene displays many fascinating properties that can be
tuned by varying the relative angle (also called twist angle) between its
monolayers. As a remarkable feature, both the electronic flat bands and the
corresponding strong electron localization have been obtained at a specific
"magic" angle ($\sim 1.1^{\circ}$), leading to the observation of several
strongly correlated electronic phenomena. Such a discovery has hence inspired
the creation of a novel research field called twistronics, i.e., aiming to
explore novel physical properties in vertically stacked 2D structures when
tuning the twist angle between the related layers. In this paper, a
comprehensive and systematic study related to the electronic properties of
twisted multilayer graphene (TMG) is presented based on atomistic calculations.
The dependence of both the global and the local electronic quantities on the
twist angle and on the stacking configuration are analyzed, fully taking into
account atomic reconstruction effects. Consequently, the correlation between
structural and electronic properties are clarified, thereby highlighting the
shared characteristics and differences between various TMG systems as well as
providing a comprehensive and essential overview. On the basis of these
investigations, possibilities to tune the electronic properties are discussed,
allowing for further developments in the field of twistronics.
