Nuclear wavepacket bifurcation as observed with time-resolved photoelectron spectroscopy

2 Nuclear wavepacket bifurcation as observed with time-resolved photoelectron spectroscopy 

In Sec. 3.3 we have shown how the nuclear wavepacket d3mamics on a single electronic state can be tracked in real-time with use of the time-resolved photoelectron spectroscopy. Here in this section we extend the theory to cope with nonadiabatic d3mamics and explore how the associated wavepacket bifurcation can be observed in this spectroscopy. 

1 Coupled nuclear dynamics on diabatic potential energy surfaces 

When the neutral states to be probed are coupled through nonadiabatic interaction, we need some way of including them in our formalism. In the adiabatic picture, the time-dependent Schrodinger equation for the nuclear wavefunctions x(il, t), which is a column vector 

A straightforward way of putting Eq. (5.4) into a form better suited for numerical computation is to make an attempt to put away the nonadiabatic off-diagonal elements through a unitary transformation, 

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