  The temperature-induced structural and electronic transformation in VO$_2$
between the monoclinic M1 and tetragonal rutile phases was studied by means of
\textit{ab initio} molecular dynamics, based on density functional theory with
Hubbard correction (DFT+U). Analysis of the dynamical processes associated with
the structural transformation was carried out on the atomic scale by following
the time evolution of dimerization amplitudes of vanadium atom chains and the
twisting angle of vanadium dimers. The electronic transition was studied by
tracing the changes in projected densities of states and their correlation with
the evolution of the structural transformation. Our results reveal a strong
interconnection between the structural and electronic transformations and show
that they take place on the same time scale.
