TOWARDS A WITTGENSTEINEAN LADDER FOR THE UNIVERSAL VIRTUAL CLASSROOM (UVC)

The aim of this work is to move from the foreign dominated to the self-dominated by encouraging people to draw their own conclusions with the help of own rational consideration. Here a room as an environment that is encouraging innovation, which can be denoted as “Innovation Lab”, and making processes as can be regarded as “Smart Lab” is an essential base. The question related to this generalized self-organizational learning method investigated in our paper is how a UVC, which is a room that connects people from different physical places to one synchronous and virtual perceivable place, which is built on these preconditions, can be operated both resource and learning-efficient for both the course participants and the educational organization. A practical approach of implementing a virtual classroom concept, including informative tutorial-feedback, is developed conceptually that also accounts for and implements the results of reinforcement machine-learning methods in AI applications. The difference that makes the difference is gained by reimplementing the AI tools in an AI instrument, in a “Smart Lab” environment and that in the teaching environment. By means of this, a cascaded feedback-loop system is informally installed, which gains feedback at different levels of abstraction. By this learning on each stage, in a collaborative and together decentralized and sequential fashion takes place, as the selforganizational implementations lead implicitly, also by means of the in the course implemented tools, to increasingly self-control. As such in the course, a tool is implemented, as generalizations by means of reinforcement learnings are to be emergently foreseen by this method, which goes beyond the tools, that have already been implemented before. This AI-enhanced learning coevolution shall then, predictively, as well increase the potential of the course participants as the educational organization according to the Wittgensteinean parable: A ladder leading into a selfly-organized future

Photoionization of endohedral atoms: Molecular and interchannel-coupling effects

Calculations of the photoionization cross section of the 2p and 3s subshells of free Ar and Ar@C-60 as examples have been performed using the molecular structure of the confined system and time-dependent density functional theory for the dynamical quantities. The results for Ar 2p in the combined system exhibit significant confinement resonances with the lower-energy ones being quite sharp, in contrast to the results of jellium-model calculations. In addition, calculations done with and without interchannel coupling between the photoionization channels of the 2p subshell of the Ar atom and the 1s subshell of the C-60 shell show that, in this case, the coupling is of negligible importance, even though the C 1s cross section is more than an order of magnitude larger than that of Ar 2p in the 300 eV range. The Ar 3s, which is not hybridized, also exhibits confinement resonances, but is very strongly affected by interchannel coupling with photoionization channels from the C-60 shell. The phenomenology of both 2p and 3s subshells is explained in terms of the interchannel-coupling matrix elements. These results should be applicable to inner-shell ionization of essentially any endohedral fullerene system

Relationship between polarization-averaged molecular-frame photoelectron angular distributions and geometry

We present a theoretical study of vibrationally resolved and unresolved molecular-frame photoelectron angular distributions (MFPADs) resulting from K-shell photoionization of N2, CO, C2H2, NH3, CH4, CF4, BF3, and SF6 in the range of photoelectron energies 0–500 eV. We show that the MFPADs of NH3 and CH4, averaged over the polarization direction, image the molecular geometry at very low energies but also at selected higher energies. For all other molecules, the MFPADs do not image the system’s geometry. However, for molecules containing heavy atoms in the periphery, CF4, BF3, and SF6, and for N2 and CO, the polarization-averaged MFPADs reflect the partial accumulation of the photoelectron density in the region surrounded by the peripheral atoms. For energies at which this accumulation occurs, the MFPADs encode information about the three dimensional arrangement of the system. In general, the polarization averaged MFPADs remain quite anisotropic even at photoelectron energies as high as 500 eVThis work was supported by the Advanced Grant of the European Research Council XCHEM 290853, the MICINN Projects No. FIS2010-15127 and No.CSD 2007-00010 (Spain), the ERA-Chemistry Project PIM2010EEC-00751, the European Grant MC-ITN CORINF, and the European COST Actions CM0702 and CM120

Alignment-Dependent Ionization of N2_2, O2_2, and CO2_2 in Intense Laser Fields

The ionization probability of N$_2$, O$_2$, and CO$_2$ in intense laser fields is studied theoretically as a function of the alignment angle by solving the time-dependent Schr\"odinger equation numerically assuming only the single-active-electron approximation. The results are compared to recent experimental data [D.~Pavi{\v{c}}i{\'c} et al., Phys.\,Rev.\,Lett.\ {\bf 98}, 243001 (2007)] and good agreement is found for N$_2$ and O$_2$. For CO$_2$ a possible explanation is provided for the failure of simplified single-active-electron models to reproduce the experimentally observed narrow ionization distribution. It is based on a field-induced coherent core-trapping effect.Comment: 5 pages, 2 figure

Wavelength- and alignment-dependent photoionization of N2 and O2

The ionization behavior of the two diatomic molecules nitrogen and oxygen in strong laser fields has been investigated. For this purpose, the time-dependent Schr\uf6dinger equation is solved numerically within the many-electron single-determinant approximation. Three different orientations of the molecular axis with respect to the laser field have been considered: 0 18,45 18, and 90 18. The photon wavelength has been varied from 25 to 800 nm, covering a range from XUV to infrared radiation. Nitrogen and oxygen were chosen as they possess the same molecular symmetry but different orbital structures. The ionization from different orbitals is discussed

Density Functional Theory for the Photoionization Dynamics of Uracil

Photoionization dynamics of the RNA base Uracil is studied in the framework of Density Functional Theory (DFT). The photoionization calculations take advantage of a newly developed parallel version of a multicentric approach to the calculation of the electronic continuum spectrum which uses a set of B-spline radial basis functions and a Kohn-Sham density functional hamiltonian. Both valence and core ionizations are considered. Scattering resonances in selected single-particle ionization channels are classified by the symmetry of the resonant state and the peak energy position in the photoelectron kinetic energy scale; the present results highlight once more the site specificity of core ionization processes. We further suggest that the resonant structures previously characterized in low-energy electron collision experiments are partly shifted below threshold by the photoionization processes. A critical evaluation of the theoretical results providing a guide for future experimental work on similar biosystems

Accurate photoionisation cross section for He at non-resonant photon energies

The total single-photon ionisation cross section was calculated for helium atoms in their ground state. Using a full configuration-interaction approach the photoionisation cross section was extracted from the complex-scaled resolvent. In the energy range from ionisation threshold to 59\,eV our results agree with an earlier $B$-spline based calculation in which the continuum is box discretised within a relative error of $0.01\%$ in the non-resonant part of the spectrum. Above the \He^{++} threshold our results agree on the other hand very well to a recent Floquet calculation. Thus our calculation confirms the previously reported deviations from the experimental reference data outside the claimed error estimate. In order to extend the calculated spectrum to very high energies, an analytical hydrogenic-type model tail is introduced that should become asymptotically exact for infinite photon energies. Its universality is investigated considering also H$^-$, Li$^+$, and HeH$^+$. With the aid of the tail corrections to the dipole approximation are estimated.Comment: 20 pages, 7 figures, 2 table

High-energy non-Franck-Condon vibrational excitation of CH4 by intramolecular photoelectron diffraction

Distinct oscillations in vibrationally resolved cross section ratios for the photoionization of CH4 from the C 1s orbital at photon energies as high as 1keV are predicted. The oscillations are attributed to the different relative vibrational excitation due to the scattering of the photoelectron by the peripheral hydrogen atoms. The latter effect is also responsible for the well known EXAFS oscillations in the integrated photoelectron spectrum. The calculations are performed with an ab-initio DFT method [1], as well as with a single-particle semi-analytical model, which incorporate both the effect of the nuclear recoil and of the Coulomb correction