title: A tri-atomic Renner-Teller system entangled with Jahn-Teller conical intersections.
abstract: The present study concentrates on a situation where a Renner-Teller (RT) system is entangled with Jahn-Teller (JT) conical intersections. Studies of this type were performed in the past for contours that surround the RT seam located along the collinear axis [see, for instance, G. J. Halász, Á. Vibók, R. Baer, and M. Baer, J. Chem. Phys. 125, 094102 (2006)]. The present study is characterized by planar contours that intersect the collinear axis, thus, forming a unique type of RT-non-adiabatic coupling terms (NACT) expressed in terms of Dirac-δ functions. Consequently, to calculate the required adiabatic-to-diabatic (mixing) angles, a new approach is developed. During this study we revealed the existence of a novel molecular parameter, η, which yields the coupling between the RT and the JT NACTs. This parameter was found to be a pure number η = 22/π (and therefore independent of any particular molecular system) and is designated as Renner-Jahn coupling parameter. The present study also reveals an unexpected result of the following kind: It is well known that each (complete) group of states, responsible for either the JT-effect or the RT-effect, forms a Hilbert space of its own. However, the entanglement between these two effects forms a third effect, namely, the RT/JT effect and the states that take part in it form a different Hilbert space.
authors: Department of Information Technology, University of Debrecen, H-4010 Debrecen, P.O. Box 12, Hungary.
authors: A
authors: A
authors: Csehi
authors: A
authors: A
authors: Bende
authors: G J
authors: GJ
authors: Halász
authors: Á
authors: Á
authors: Vibók
authors: A
authors: A
authors: Das
authors: D
authors: D
authors: Mukhopadhyay
authors: M
authors: M
authors: Baer
mesh_terms: D000465:Algorithms; D008956:Models, Chemical; D011789:Quantum Theory; D013816:Thermodynamics