Intersections of potential energy surfaces of short-lived states:The complex analogue of conical intersections

摘要

Whereas conical interesections between potential energy surfaces of bound states are well known,the interaction of short-lived states ahs been investigated only rarely.Here,we present several systematically constructed model Hamiltonians to study the topology of interescting complex potential energy surfaces describing short-lived states:We find the general phenomenon of doubly intersecting complex energy surfaces,i.e.,there are two points instead of one as in the case of bound states where the potential energy surfafces coalesce.In addition,seams of intersections of the respective real and imaginary parts of the potential energy surfaces emanate from these two points.Using the SIGMA~* and II~* resonance states of the chloroethene anion as a practical example,we demonstrate that our complete linear model Hamiltonian is able to reproduce all phenomena found in explicitly calculated ab initio complex potential energy surfaces.