  Vacancy dynamics in oxides are vital for understanding redox reactions and
resulting memristive effects or catalytic activity. We present a method to
track and drive vacancies which we apply to metadynamics simulation of oxygen
vacancies (V$_{\mathrm{O}}$) in rutile, demonstrating its effectiveness. Using
the density functional based tight binding method, it is possible to explore
the free energy hyperplane of oxygen vacancies in TiO$_{2}$. We show that the
migration of V$_{\mathrm{O}}$ in TiO$_{2}$ is governed by the jump with the
higherst number of realizations. Free energy profiles are consistent with
minimum energy paths.
