Because the α part of Hartree-Fock density ρ is not equal to the β part for open-shells, the symmetry between h SOM F,2e ± is broken. Table shows numerical consequences of such violation. Fortunately, regardless of the size of the system or of the number of unpaired electrons in the reference, the extent of such violation does not exceed 0.05 cm -1 for the reduced matrix elements. To eliminate its influence on SOCC and splittings, we used arithmetic averaging for S||H L -||S and S||H L + ||S , similar to Eq. .