On the basis of the AME2020 data we consider the mass relations such as $\Delta_{np}$, $\delta V_{np}$ and Harvey-Kelson relations that are associated with neutron-proton correlations and can be used to predict masses of unknown atomic nuclei. The behavior of these characteristics is analyzed within the framework of the liquid drop model and in the Hartree-Fock microscopic approach in comparison with modern experimental data. New approximations of $\Delta_{np}$ and $\delta V_{np}$ as functions of the mass number $A$ are obtained.
$^1$D.V.Scobeltsyn Institute of Nuclear Physics,Lomonosov Moscow State University,\
$^2$Moscow State University, Physics Faculty
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