The Linac Coherent Light Source (LCLS) X-ray free-electron laser at SLAC produces ultra-short laser pulses with extremely high peak intensity in both the soft and hard X-ray regime. The unique properties of LCLS can be used to create Double Core-Hole (DCH) states in molecules by ejection of two inner electrons via absorption of two X-ray photons. The DCH-states, and in particular the kind where the core holes are created on separate atoms, have been predicted to be very useful for chemical analysis because of their high sensitivity to the local chemical environment. In this project we created DCH-states in a series of small molecules and experimentally investigated their chemical sensitivity. I will present these results and also shortly describe LCLS.
