Dataset pertaining to the manuscript "How does Mg2+(aq) interact with ATP(aq)? Observations through the lens of liquid-jet photoelectron spectroscopy", submitted to arxiv. Files with extension .h5 are hdf5-files structured according to the NeXus standard v2022.07, see https://www.nexusformat.org/ https://fairmat-experimental.github.io/nexus-fairmat-proposal/50433d9039b3f33299bab338998acb5335cd8951/mpes-structure.html NeXus data files can be opened with any software capable of opening hdf5-structured files. The following viewers are adapted to the specifics of the NeXus data format: * nexpy (distributed with python) * https://h5web.panosc.eu/h5wasm (web-based NeXus viewer maintained by the European Photon and Neutron Open Science Cloud-consortium) In each NeXus file-entry, two types of spectra are shown: 1. Sweep-averaged spectra, integrated over the non-dispersive coordinate of our detector ('data'). For ATP spectra, the ADP overview spectrum, and ADP/Mg2+ Mg 2s spectra, a binding energy correction shifting the liquid 1b1 feature to 11.33 eV is applied. 2. As-measured data ('raw'). Files with extension .txt are comma-separated ascii-files. The following files are provided: Photoemission data pertaining to adenosine phosphate PES measurements: atp-mg.h5 - ATP photoemission spectra in the presence of Mg2+ cations in varying concentration adp-mg.h5 - ADP photoemission spectra in the presence of Mg2+ cations in varying concentration amp-mg.h5 - AMP photoemission spectra in the presence of Mg2+ cations (a single concentration) atp-adp-amp.h5 - ATP, ADP, AMP photoemission without Mg admixture mg-only.h5 - Mg 2s core level spectra without ATP tham-only.h5 - VB band measured with only THAM (tris(hydroxymethyl)aminomethane), used as buffer for pH stabilization Numeric representations of the traces shown in the manuscript's figures: Figure_2-data.txt Figure_4a-Mg2p.txt Figure_4a-Mg2s.txt Figure_4a-Mgonly.txt Figure_4a-P2p.txt Figure_4a-P2s.txt Figure_4b-ATP.txt Figure_4b-Mg2ATP.txt Figure_4b-MgATP.txt Figure_7-data.txt Figure_S2...txt Figure_S4-data.txt Contact: Uwe Hergenhahn, uhe@fhi.mpg.de .
X-ray single-photon ionization and fragmentation of the chiral molecule halothane from a racemic mixture have been investigated using the cold target recoil ion momentum spectroscopy technique. Two important facets related to the core ionization of this species are examined: Firstly, the distinction of enantiomers (mirror isomers) and the determination of absolute configuration on a single-molecule level by four-body Coulomb explosion; secondly, the interplay of site-selective excitation and fragmentation patterns. These results are easily transferable to other molecular species and show the wealth of features that can be investigated by coincidence spectroscopy of chiral molecules.
We present a study on molecular-frame photoelectron angular distributions (MFPADs) of small molecules using circularly polarized synchrotron light. We find that the main forward-scattering peaks of the MFPADs are slightly tilted with respect to the molecular axis. This tilt angle is directly connected to the molecular bond length by a simple, universal formula. We apply the derived formula to several examples of MFPADs of C 1s and O 1s photoelectrons of CO, which have been measured experimentally or obtained by means of ab initio modeling. In addition, we discuss the influence of the back-scattering contribution that is superimposed over the analyzed forward-scattering peak in the case of homo-nuclear diatomic molecules such as N2.
Within a joint experimental and theoretical research project, double photoionization of the He-like B3+ ion by a single photon was studied in the energy range from approximately 350 to 1160 eV. With the parent-ion beam in the experiment containing both 1s21S ground-state (90.9%) and 1s2sS3 metastable B3+ ions (9.1%), two contributions to the apparent single- and double-ionization cross sections, σ34app and σ35app, respectively, are involved in the measurements. Ratios Y(5+)/Y(4+) of double- over single-ionization yields were experimentally determined. By multiplying the measured ratios by the known cross section σ34app, the apparent cross section σ35app for double ionization was inferred. Using the information thus obtained, the measured yield of B5+ ions produced from hydrogenlike B4+ could also be normalized. The results show good agreement with theoretical benchmark cross sections σ45 for single photoionization of B4+. Convergent close-coupling calculations were performed to determine double-photoionization cross sections σ35 for B3+(1s2) and B3+(1s2s) ions. The result for the ground state agrees very well with theoretical data obtained previously with an intermediate-energy R-matrix approach. Within the systematic uncertainty of the normalized experimental cross sections, calculated and measured data are in agreement with one another. Published by the American Physical Society 2025
It's well known for atomic targets that the ionization in transfer ionization originates from electron knock-off or initial state correlated shake-off. For H2 molecules we have observed a similar behavior and additionally a dependency of the electron emission from the internuclear axis
Experimental cross sections for m-fold photodetachment (m=2-5) of oxygen anions via K-shell excitation and ionization were measured in the photon-energy range of 525-1500 eV using the photon-ion merged-beams technique at a synchrotron light source. The measured cross sections exhibit clear signatures of direct double detachment, including double K-hole creation. The shapes of the double-detachment cross sections as a function of photon energy are in accord with Pattard's [J. Phys. B 35, L207 (2002)] empirical scaling law. We have also followed the complex deexcitation cascades that evolve subsequently to the initial double-detachment events by systematic large-scale cascade calculations. The resulting theoretical product charge-state distributions are in good agreement with the experimental findings.
It is commonly accepted that the magnitude of a photoelectron circular dichroism (PECD) is governed by the ability of an outgoing photoelectron wave packet to probe the chiral asymmetry of a molecule. To be able to accumulate this characteristic asymmetry while escaping the chiral ion, photoelectrons need to have relatively small kinetic energies of up to a few tens of electron volts. Here, we demonstrate a substantial PECD for very fast photoelectrons above 500 eV kinetic energy released from methyloxirane by a participator resonant Auger decay of its lowermost O $1s$ excitation. This effect emerges as a result of the Fano interference between the direct and resonant photoionization pathways, notwithstanding that their individual effects are negligibly small. The resulting dichroic parameter has an anomalous dispersion: It changes its sign across the resonance, which can be considered as an analogue of the Cotton effect in the x-ray regime.
Abstract Metastable states of ions can be sufficiently populated in absorbing and emitting astrophysical media, enabling spectroscopic plasma-density diagnostics. Long-lived states appear in many isoelectronic sequences with an even number of electrons, and can be fed at large rates by various photonic and electronic mechanisms. Here, we experimentally investigate beryllium-like and carbon-like ions of neon and iron that have been predicted to exhibit detectable features in astrophysical soft X-ray absorption spectra. An ion population generated and excited by electron impact is subjected to highly monochromatic X-rays from a synchrotron beamline, allowing us to identify K α transitions from metastable states. We compare their energies and natural line widths with state-of-the-art theory and benchmark level population calculations at electron densities of 10 10.5 cm −3 .
We investigate the contribution of interatomic Coulombic decay induced by ion impact in neon and argon dimers (Ne${}_{2}$ and Ar${}_{2}$) to the production of low-energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S${}^{14+}$, 0.125 MeV/u He${}^{1+}$, 0.1625 MeV/u He${}^{1+}$, and 0.150 MeV/u He${}^{2+}$ as projectiles and study ionization, single and double electron transfer to the projectile, as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentum vectors of the ion pairs of the fragmenting dimer into Ne${}^{q+}$-Ne${}^{1+}$ and Ar${}^{q+}$-Ar${}^{1+}$ ($q=$ 1, 2, 3) in coincidence with at least one emitted electron.
Data set pertaining to the article "Quantitative electronic structure and work-function changes of liquid water induced by solute" | Physical Chemistry Chemical Physics, 24, 1310 (2022). Files with extension .h5 are hdf5-files structured according to the NeXus standard v2022.07 using the NXmpes user contributed format suggested by the Fairmat consortium, see https://www.nexusformat.org/ https://fairmat-experimental.github.io/nexus-fairmat-proposal/50433d9039b3f33299bab338998acb5335cd8951/mpes-structure.html A few extensions specific to liquid jet-experiments were added to the standard, and are explained in the notes-group on the top level of each file. NeXus data files can be opened with any software capable of opening hdf5-structured files. The following viewers are adapted to the specifics of the NeXus data format: * nexpy (distributed with python) * https://h5web.panosc.eu/h5wasm (web-based NeXus viewer maintained by the European Photon and Neutron Open Science Cloud-consortium) In each NeXus file-entry, two types of spectra are shown: 1. Sweep-averaged spectra, integrated over the non-dispersive coordinate of our detector ('data'). 2. As-measured data ('raw'). Files with extension .txt are comma-separated ascii-files. The following files are provided: Photoemission data pertaining to solute measurements using the cut-off as energy reference: NaI_data.h5 tbai_data.h5 Biased spectra were typically recorded in the following order: [cut-off (fine), cut-off (coarse), (valence band)*(N repeats)]*(M repeats) To avoid the saving of overly complex hdf5-files, these data were saved in a different order, namely: [cut-off (fine)*(M repeats), cut-off (coarse)*(M repeats), (valence band)*(N*M repeats)]. Numeric representations of the traces shown in the article's figures: Figure_1a-data.txt Figure_1b-data.txt Figure_2a-data.txt Figure_2b-data.txt Figure_2c-data.txt Figure_3-data.txt Figure_4-data.txt Figure_5a-data.txt Figure_5b-data.txt Figure_6a-data.txt Figure_6b-data.txt Figure_6c-data.txt Figure_7_diff_spectra-data.txt Figure_8-data.txt Traces shown in several figures are included only in the data file pertaining to the figure in which they occur first. Contact: Uwe Hergenhahn, uhe@fhi.mpg.de .
