Using time-resolved photoelectron spectroscopy to benchmark excited state molecular dynamics calculations

A TRPES (time-resolved photoelectron spectroscopy) experiment was performed to compare trajectory surface hopping calculations for three different levels of theory (CASSCF, MRCIS, and XMS-CASPT2). In particular, we consider the radiationless decay following excitation to the first bright state of uracil (S₂). The measurements allow us to track independently the excitation and decay of S₁ and S₂ and discriminate between different levels of theory.