Correction to Relativistic Mean Field binding energy and NpNnNpNn scheme

The differences between the experimental and Relativistic Mean Field binding energies have been calculated for a large number of even–even nuclei from A=50A=50 to 220. Excluding certain mass regions, the differences, after suitable corrections for particular isotope chains, are found to be proportional to the Casten factor P  , chosen as a measure of n–pn–p interaction strength in a nucleus. Results for even-Z odd-N   nuclei are also seen to follow the same relation, if the odd–even mass difference is taken into account following the semiempirical formula. This indicates that the n–pn–p interaction is the major contributor to the difference between the calculated and the experimental binding energies.