After the TSRC workshops in 2007 and 2013 this is the third workshop devoted to the phase space structures that govern the dynamics of reactions. These workshops have been triggered by the geometric insight from dynamical systems theory that has led to a rigorous realisation of Transition State Theory. It comprises a solution to the longstanding problem of how to construct of a recrossing-free dividing surface for multi-degree-of-freedom systems. It has been shown that such a dividing surface spans a normally hyperbolic invariant manifold (NHIM) which is induced by a saddle-type equilibrium that is characteristic for reaction dynamics. The NHIM can be viewed as a generalisation of the unstable periodic orbit which has led to the rigorous realisation of Transition State Theory for 2-degree-of-freedom systems in terms of a periodic orbit dividing surface (PODS) as has been shown in the 1970’s. The NHIM has stable and unstable manifolds which mediate reactions in the sense that they form tubes that channel trajectories from reactants to products and separate them from non-reactive trajectories. The stable and unstable manifolds allow one at least in principle to study key questions in reaction dynamics like the dynamical origin of non-RRKM behaviour and state specific reactivity.

In the present workshop we want to highlight the latest results and discuss future perspectives. This includes the bifurcations of transition states, mechanisms for the break down of Transition State Theory, coupling of reacting systems to a heat bath, dynamical implications of higher index saddles, transition states resulting from relative equilibria, the quantum mechanics of reactions, non-RRKM behaviour, computation of NHIMs and their stable and unstable manifolds, and specific applications.

Special emphasis will be laid on the workshop character of the meeting by leaving ample time for discussions and stimulating collaborations between the participants in addition to presentations on the latest developments in the field.