To provide a brief outline of this discussion, it is worth mentioning works related to the ambiguity of the concepts of ionicity and covalency in chemical bonds, as well as attempts to explain the covalency of the bond in the hydrogen molecule and other diatomic molecules. Our contribution to this discussion has been to provide the complementary characteristics of the chemical bond such as the atomicity and true covalency or our newest paper about entanglement correlations as the alternative bonding characteristic. In this paper, we use the EDABI approach to investigate the detailed electronic structure of hydrogen-based molecular systems, specifically H + 2 , H 2 , and H - 2 . We employ the formalism of second quantization to express the Hamiltonian and wavefunctions, enabling a clear and concise representation of the electronic states. The Hamiltonian we consider includes all twoelectron interactions in the Fock space that appear in the two-orbital model of the Heitler-London type.