  The natural orbitals renormalization group (NORG) has previously been
proposed as an efficient numerical method for solving zero-temperature
properties of multisite and multiorbital quantum impurity systems. Here, we
implement the NORG as an impurity solver for dynamical mean-field theory
(DMFT). In comparison with the exact diagonalization method, the NORG method
can treat much more bath sites in an impurity model to which the DMFT maps a
lattice model and can find accurate zero-temperature Matsubara and
low-frequency retarded Green's functions. We demonstrate the effectiveness of
this method on a two-orbital Hubbard model on the Bethe lattice and find
successfully the orbital selective Mott transition with a Kondo resonance peak
in the wide band and two holon-doublon bound state excitation peaks in the
narrow band.
