  The density matrix renormalization group (DMRG) method has already proved
itself as a very efficient and accurate computational method, which can treat
large active spaces and capture the major part of strong correlation. Its
application on larger molecules is, however, limited by its own computational
scaling as well as demands of methods for treatment of the missing dynamical
electron correlation. In this work, we present the first step in the direction
of combining DMRG with density functional theory (DFT), one of the most
employed quantum chemical methods with favourable scaling, by means of the
projection-based wave function (WF)-in-DFT embedding. On the two
proof-of-concept but important molecular examples, we demonstrate that the
developed DMRG-in-DFT approach provides a very accurate description of
molecules with a strongly correlated fragment.
