Ground-state wave function conical intersections

Comparison between the first and last lines of the table shows that the sign of the ground-state wave function has been reversed, which implies the existence of a conical intersection somewhere inside the loop described by the table. 

A direct way of probing the conical intersection of H3 X E ) are Rydberg emission spectra, is Here the initial electronic state has (approximately) Dsh geometry. The conical intersection in the final (ground) electronic state thus falls into the FC zone of the electronic transition. The situation is depicted in the upper panel of Fig. 7 which shows the potential energy surfaces of initial and final electronic states as a function of the distance between one H-atom and the centre of the H2 moiety (for perpendicular approach and fixed vh-h distance as indicated in the panel). The conical intersection is represented by the curve crossing at R = yf rj2 K, 1.42 au and seen to coincide with the maximum of the initial state wave function which is also included in the drawing. 

Single surface calculations with a vector potential in the adiabatic representation and two surface calculations in the diabatic representation with or without shifting the conical intersection from the origin are performed using Cartesian coordinates. As in the asymptotic region the two coordinates of the model represent a translational and a vibrational mode, respectively, the initial wave function for the ground state can be represented as. 

---