Unlocking the Double Bond in Protonated Schiff Bases by Coherent Superposition of S₁ and S₂

The primary event occurring during the E-to-Z photoisomerization reaction of retinal protonated Schiff base (rPSB) is single-to-double bond inversion. In this work we examine nuclear dynamics that occurs when initial excited state a superposition S1 and S2 electronic states might be created in laser experiment. dominated by double inversion parallel to derivative coupling vector S2. Thus, molecule behaves as if it were at conical intersection even are nondegenerate.