Time-resolved photoelectron spectroscopy from first principles: Excited state dynamics of benzene

Abstract

We use the ab initio multiple spawning (AIMS) method to follow the dynamics of benzene after excitation to the second singlet excited state (S2). The results are validated by comparison to potential energy surfaces including dynamical electron correlation effects. Time-resolved photoelectron spectra are computed and compared to experimental results. Simulations agree with experiment that there are both short-lived and long-lived components of the excited state population. We show that these components both originate from quenching through the same S2/S1 conical intersection and that the difference between them comes from their behavior immediately after decay to S1. This is presumed to be a function of the details of the way in which the S2/S1 intersection region is accessed; for example, the momentum distribution and the topology of the seam in the relevant region.

Probing electronic and vibrational dynamics in molecules by time-resolved photoelectron, Auger-electron, and X-ray photon scattering spectroscopy

“…This approach has the advantage of being very intuitive and is readily amenable to semiclassical treatments. Similar formulas have been used to study the nuclear dynamics on the excited singlet state potential energy surfaces of a variety of molecules [14, 15]. …”

Hexamethylcyclopentadiene: time-resolved photoelectron spectroscopy and ab initio multiple spawning simulations

“…Many model systems have been investigated by time-resolved experiments [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] or dynamical simulations. [20][21][22][23][24][25][26] We believe that fundamental questions could be answered more easily by joint studies connecting experimental approaches with such simulations. However, very few studies of this type have been carried out so far.…”

Coherent phase control of internal conversion in pyrazine

“…[37] Using the ab initio multiple spawning method, Thompson and Martinez showed how the fluorescence decay rate of benzene depends on the WP trajectory, with part of the population trapped in a minimum in the S 1 surface before reaching the seam. [40] There is a large literature on vibrational control of the reactivity of electronically excited molecules, including, but not restricted, to vibrationally adiabatic reactions. Of particular interest here are studies that demonstrate the control of radiationless transitions by shaping the WP in the FC region.…”