Atomic and Molecular Clusters
We describe a setup to study ultrafast dynamics in gas-phase molecules using time-resolved photoelectron and photoion spectroscopy. The vacuum ultraviolet (VUV) probe pulses are generated via strong field high-order harmonic generation from…
The charge ordering (CO) transition in polycrystalline La1/3Sr2/3MnO3 has been studied by measuring the resistivity, magnetization and transverse ultrasonic velocity. At about 235K, a conspicuous increase in resistivity was observed, while…
Utilising Car-Parrinello molecular dynamics simulations, the finite temperature behaviour of water trimers, (H2O)3, in both neutral and anionic frameworks, has been investigated. A significant structural change in the anionic structure has…
It is a long-standing dream of scientists to capture the ultra-fast dynamics of molecular or chemical reactions in real time and to make a molecular movie. With free-electron lasers delivering extreme ultraviolet (XUV) light at…
Low-energy electrons (LEEs) are known to be effective in causing strand breaks in DNA. Recent experiments show that an important direct source of LEEs is the intermolecular Coulombic decay (ICD) process. Here we propose a new cascade…
The generation of organic particle beams is studied in combination with photoionization using uv radiation at 266 nm and vuv light at 157 nm. Single-photon ionization with pulsed vuv light turns out to be sensitive enough to detect various…
We present a proof-of-principle study of superconducting single photon detectors (SSPD) for the detection of individual neutral molecules/nanoparticles at low energies. The new detector is applied to characterize a laser desorption source…
The electronic spectra of cold benzylium (C6H5-CH2+) and 1-phenylethyl (C6H5-CH-CH3+)cations have been recorded via photofragment spectroscopy. Benzylium and 1-phenylethyl cations produced from electrosprayed benzylamine and…
Multipole electron modes beyond the Mie plasmon in atomic clusters are investigated within the time-dependent local density approximation theory (TDLDA). We consider the origin of the modes, their connection with basic cluster properties…
A simple scheme of population and detection of low-lying electronic quadrupole modes in free small deformed metal clusters is proposed. The scheme is analyzed in terms of the TDLDA (time-dependent local density approximation) calculations.…
We are presenting vibrationally selective pump-probe measurements of the first electronic excited-state (pp*) lifetime of jet-cooled neutral catechol (1,2-dihydroxybenzene). The lifetime of the 0-0 transition is very short (7 ps) as…
It has been observed that the trajectory of a H2 molecular beam is modified as it passes through a homogeneous magnetic field and an oscillating magnetic field. Based on this observation, this work describes a new method to determine the…
TThe stability of Ngn@B12N12 and Ngn@B16N16 systems is assessed through a density functional study and ab initio simulation. Although they are found to be thermodynamically unstable with respect to the dissociation of individual Ng atoms…
The Controlled Molecule Imaging group (CMI) at the Center for Free Electron Laser Science (CFEL) has developed the CMIstark software to calculate, view, and analyze the energy levels of adiabatic Stark energy curves of linear, symmetric top…
The use of powerful hydrogen cluster jet targets in storage ring experiments led to the need of precise data on the mean cluster velocity as function of the stagnation temperature and pressure for the determination of the volume density of…
The newly developed compound ExBox4+ is explored to check whether it is a proficient hydrogen storage material. Both exoherdal and endohedral hydrogen adsorption on ExBox4+ are studied. Endohedral hydrogen molecules interact strongly than…
The structural properties of the uranium-encapsulated nano-cage U@Au14 are predicted using density functional theory. The presence of the uranium atom makes the Au14 structure more stable than the empty Au14-cage, with a triplet ground…
High harmonic generation is a convenient way to obtain extreme ultraviolet light from table-top laser systems and the experimental tools to exploit this simple and powerful light source for time-resolved spectroscopy are being developed by…
Water clusters are known to form through hydrogen bonding. However, this study shows that the formation of very small water clusters significantly deviates from this mechanism and instead involves both hydrogen bonding and electron…
We investigate the ionization of HeNe from below the He 1s3p excitation to the He ionization threshold. We observe HeNe$^+$ ions with an enhancement by more than a factor of 60 when the He side couples resonantly to the radiation field.…