7 Numerical examples As the first step in validating the implemented MRF solver, in given by Eq. 41 with F given by Eq. 42]; and 'MRF optimized' [the fluctuation function given by Eq. 56 with 0.26, see Fig. ]. All MRF energies have been calculated on the Hartree-Fock densities within the TZVP basis set 51 by using the MRF solver described in Sec. 6 The reference values (last column) have been calculated from CCSD and are taken from Ref. .