Multi-electron effects in the dynamics of resonant states of molecules

Advisor: Zdeněk Mašín (ITP MFF CUNI)

Funding: Fully funded

Website: http://utf.mff.cuni.cz/~zmasin

Scattering resonances initiate and enhance molecular processes including molecular breakup in various environments ranging from plasmas to cells in the human body [1]. The aim of this project is to understand the properties of electronically inelastic resonant states formed in collisions of low-energy electrons with complex molecules or in molecular photoionization. The formation of those states requires a rearrangement of multiple electrons and is not fully understood [2] and the way in which they affect molecular breakup is also largely unknown. We will use state of art ab initio R-matrix method [3] and complementary analytic modeling to explore the structure of these resonances.

Recently, we have extended our codes to calculations in the complex energy plane and developed a method to find all elastic resonant and virtual states (Siegert states) in molecules [4]. In this project we will extend the method to the much more demanding electronically inelastic regime and use it to characterize and visualize the inelastic resonant states in detail including their dependence on the molecular geometry. This will include tracking the motion of the S-matrix poles on the Riemann surface as a function of molecular geometry and investigating the consequences of pole removal for the observables on the real energy axis. Where possible, we will model properties of these resonances by constructing simple models.

This work will contribute to the understanding of the role of electronically inelastic resonances to breakup reactions in various molecules including the building blocks of the DNA. The photoionization part will be explored in close relation to applications in ultrafast (attosecond) physics.

This project is suitable for an enthusiastic student who is keen to study in detail quantum physics of collision processes and quantum chemistry and would enjoy developing and running codes on supercomputers. This work includes a collaborative component on the code development with our colleagues from the UK.

References:

[1] B.D. Michael and P. O’Neill, Science 287, 1603 (2000); B. Boudaïffa, P. Cloutier, D. Hunting, M.A. Huels, and L. Sanche, Science 287, 1658 (2000).
[2] Z. Mašín and J.D. Gorfinkiel, The Journal of Chemical Physics 137, 204312 (2012).
[3] Z. Mašín, J. Benda, J.D. Gorfinkiel, A.G. Harvey, and J. Tennyson, Computer Physics Communications 249, 107092 (2020).
[4] To be published; the original method is described in: L.A. Morgan and P.G. Burke, J. Phys. B: At. Mol. Opt. Phys. 21, 2091 (1988).