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Tuesday, 25 November 2014

Morgane: DM: Effect of nuclear distribution on electron dynamics.

Electron dynamics following ionisation is often simulated at a single nuclear geometry, the equilibrium geometry of the neutral species. However, even in the vibrational ground state, there is a distribution of nuclear geometries. We have sampled the initial distribution with hundreds geometries and simulated the electron dynamics at each of them. In toluene cation, we observe a fast decoherence of the electronic superposition: the average oscillation in the electronic density is damped.

Tuesday, 11 November 2014

Renjie: DM: Ab initio calculation of Penning ionization widths for millikelvin atom-molecule collisions

Penning ionization is a fundamental collision process between two neutral species. One of the atoms or molecules is electronically excited so that the whole system is above the ionization threshold, resulting in an auto-ionization process. The ionization width of the process is calculated using a combination of algebraic diagrammatic construction, Stieltjes imaging, Davidson and Lanczos diagonalization algorithms. This project is motivated by an observation of Penning ionization at sub-kelvin temperatures (see the link below).

Tuesday, 4 November 2014

Daniel: DM: Third harmonic enhancement of VUV generation

I will report on simulations that suggest sub-femtosecond VUV pulse generation can be enhanced by mixing the driving IR field with its third harmonic. Previous experimental work has shown that below threshold harmonics can boost HHG from longer pulses.