The intrinsic dynamic and static natures of the E⋯E′ interactions at the 1,8-positions of 1-(MeE)-8-(MeE′)C10H6 [1a-1f (E ≠ E′) and 1g-1j (E = E′)] were elucidated with QTAIM-DFA, after structural determination of 1-(PhE)-8-(PhE′)C10H6 (3a-3f), where (E, E′: x) = (O, S: A), (O, Se: b), (O, Te: c), (S, Se: d), (S, Te: e), (Se, Te: f), (O, O: g), (S, S: h), (Se, Se: i) and (Te, Te: j) (χE ≥ χE′). While the AB structures are confirmed for 3a, 3b and 3d-3f, which consist of the np(E)⋯σ∗(E′-CPh) interactions, the structure was BB for 3c, where the E-CR/E′-CR (R = Ph) bond is perpendicular to the naphthyl plane in A and it is placed on the plane in B. While the AB structures are determined by the p(E)-π(Ph) conjugations, the BB structure is by the crystal packing effect. The BA structure with np(E′)⋯σ∗(E-CPh) was not detected. While the nature of a typical hydrogen bond with covalency was predicted for BB, AA and BA, with the CT-MC (molecular complex formation through charge transfer) nature for AB in 1e and 1f (R = Me for E-CR/E′-CR), the CT-MC nature was predicted for all conformers of 1j, for example. NBO analysis for 1a-1f revealed that the acceptor orbitals contribute much more than the donor orbitals and the order is σ∗(O-CMe: <0.5 kcal mol-1) ≪ σ∗(S-CMe: ≈5 kcal mol-1) ≪ σ∗(Se-CMe: ≈10 kcal mol-1) ≪ σ∗(Te-CMe: ≈16 kcal mol-1) for np(S), np(Se) and np(Te). The E(2) values proportionally correlate to Cii-1 for AB and/or BA of 1a-1j, if analyzed separately for σ∗(S-C), σ∗(Se-C) and σ∗(Te-C).