Quantum chemical calculations are performed to study the bifurcated chalcogen bonding (BCB) interactions in Ph2N2O2...XCY (X=S, Se, Te and Y=O, S, Se, Te) complexes. The interaction of the only one σ-hole on X atom with two negative regions, which leads to BCB interactions, is exceptionally remarkable. The nature of the BCB interactions is probed by a variety of means, including electrostatic potentials, AIM, NBO, energy decomposition and electron density differences maps. The EDA analysis reveals that the dominant attractive force in X...O chalcogen bonded complexes is the electrostatic energy. The interaction energy values, obtained using the QTAIM-based Espinosa’s approach, provide a relatively distinguishable result than DFT method and EDA analysis reported in this study.
