The present work deals with the study of different models of bonding and structure such as Lewis, VSEPR, qualitative MO and QTAIM have been applied to analyze the Bonds and structures of two equilibrium geometries (planar D_2h and perpendicular D_2d) of C ₂ H²₄ ⁺. It is shown that the cited models fail in predicting the existence of perpendicular, D_2d form of C ₂ H²₄ ⁺. In this regard the interpretations of significant energetic stabilization of D_2d form over planar isomer has also been revisited. This is attributed to the hidden effect of the Pauli Exclusion principle.