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Cu-doped α-FeOOH dispersed activated carbon fibers were prepared and their NO adsorptivities were examined to elucidate the role of an electronic factor of the dispersed oxide in the micropore filling of supercritical NO. The nitrogen adsorption isotherms of the samples were determined and analyzed by t and Dubinin-Radushkevich plots; doping Cu2+ ions did not change significantly the microporosity of α-FeOOH dispersed activated carbon fibers. The dispersed oxides were characterized by EXAFS spectroscopy; the Cu-doped oxide on the activated carbon fibers have a local structure similar to that of α-FeOOH. The effects on NO micropore filling of doping with Cu2+ ions and preheating Cu-doped samples were examined. Addition of 1% Cu2+ ions enhanced most effectively the NO micropore filling and preheating the 3% Cu-doped α-FeOOH dispersed activated carbon fibers at 773 K enhanced remarkably the NO micropore filling. The enhancement effects on NO micropore filling of Cu doping were presumed to be associated with the defect structural change in the dispersed α-FeOOH.

Dissociative recombination of CH+ is studied by using the multichannel quantum defect theory (MQDT). The relevant electronic states were calculated by adopting the self-consistent field (SCF) and the configuration mixing (CM) methods. Particular care was taken to represent correctly the diffuse character of the excited states, especially of the two-electron excited states. The dissociative state coupled with the initial channel was found to cross the lowest potential of CH+ near the left turning point of the first excited vibrational state. The authors took into account both the p pi and d pi partial waves of the incident electron in the MQDT treatment. For this purpose, they modified the MQDT formulation by Giusti so as to fully describe the angular parts. The rate constant obtained is 1.12*10-7 cm3 s-1 at 120 K, which is about one third of the experimental value of Mitchell et al. (1978). The contribution of the d pi wave was found to be comparable to that of the p pi wave.

Charge-transfer-to-solvent (CTTS) excited states of aqueous chloride are studied by a novel experimental approach based on resonant inner-shell photoexcitation, Cl(-)aq 2p --e(i), i = 1-4, which denotes a series of excitations to lowest and higher CTTS states. These states are clearly identified through the occurrence of characteristic spectator Auger decays to double Cl 3p valence-hole states, where the CTTS states can be more stabilized as compared to single Cl(-)aq 2p core excitations and optical valence excitations. Furthermore, we have found for the first time that the CTTS electron e(i) bound by a single Cl 2p hole not only behaves as a spectator e(i) --e'(i), bound by a double valence-hole state before relaxation of the excited electron (i) itself, but also shows electron dynamics to the relaxed lowest state, e(i) --e'(1*). This interpretation is supported by ab initio calculations. The key to performing photoelectron and Auger-electron spectroscopy studies from aqueous solutions is the use of a liquid microjet in ultrahigh vacuum in conjunction with synchrotron radiation.

Ce:LuLiF4 as fast scintillator is evaluated using a storage ring free-electron laser operated in deep ultraviolet region. The response time is found to be varied for the excitation of the different absorption band.

Electron-ion-ion coincidence measurements of sulfur dioxide at discrete resonances near the O 1s ionization edge are reported. The spectra are analyzed using a model based upon molecular symmetry and on the geometry of the molecule. We find clear evidence for molecular alignment that can be ascribed to symmetry properties of the ground and core-excited states. Configuration interaction (CI) calculations indicate geometry changes in accord with the measured spectra. For the SO(2) molecule, however, we find that the localized core hole does not produce measurable evidence for valence localization, since the transition dipole moment is not parallel to a breaking sigma* O-S bond, in contrast to the case of ozone. The dissociation behavior based upon the CI calculations using symmetry-broken orbitals while fixing a localized core-hole site is found to be nearly equivalent to that using symmetry-adapted orbitals. This implies that the core-localization effect is not strong enough to localize the sigma* valence orbital.

For K-shell photoionization of neon dimers, we report Ne 1s photoelectron angular distributions for Ne2++Ne+ and Ne++Ne+ channels exhibiting quite different patterns. Noninversion-symmetric patterns of the former obtained by the fast interatomic Coulombic decay of Auger final states show direct evidence of core-hole localization. Dipolar patterns of the latter obtained by the slow radiative decay of the other Auger final states clearly show that the radiative process is slow enough to allow dicationic dimers to rotate many times before fragmentation.

Iron-containing bimetallic catalysts were prepared from carbonyl clusters as precursors deposited on SiO2. FeRh4 and Fe2Rh4 cluster-derived catalysts showed high activity and selectivity for formation of ethanol and methanol in CO hydrogenation. Fe3Pt3, Fe6Pd6 and FeIr4 cluster catalysts gave methanol in high selectivity, while Fe-rich Fe4Pt and Fe4Pd were not selective catalysts. The RhFe cluster catalysts showed improved activity in hydroformylation of olefins; C4-alcohols were substantially obtained from C3 + CO + H2. Mossbauer and EXAFS studies on the Fe2Rh4/SiO2 catalyst show that highly dispersed RhFe bimetallic particles are located on the SiO2 surface, where Fe atoms exist preferentially in the state of Fe3+ even after H2 reduction. FTIR spectra of CO chemisorbed on Fe2Rh4/SiO2 exhibit a low-frequency band possibly due to the G and O-bonded CO on Rh-Fe3+ sites. Bimetallic promotion of alcohol production in CO hydrogenation and olefin hydroformylation is proposed to originate from the two-site interaction of Rh-Fe3+ (or Pt-Fe3+, Pd-Fe3+, IrFe3+) sites with CO to enhance migratory CO insertion.

The XPS O1s spectrum of PET was examined in detail. Spectra of related compounds were also studied for comparison. The O1s peak profile of asymmetric doublet with π-π* satellites characteristic of PET was successfully explained both from comparison with the observed O1s spectra of the related compounds and from ab initio ΔSCF calculation

NaY zeolite entrapped Rh{sub 6}(CO){sub 16} and the product of its oxidation followed by reduction, (Rh{sub 6}){sub red}/NaY, have been structurally characterized by EXAFS and FTIR spectroscopies and CO/H{sub 2} chemisorption. Rh{sub 6}(CO){sub 12}({mu}{sub 3}-CO){sub 4}, (A), in NaY supercages has been synthesized with minor formation of Rh{sup +}(CO){sub 2}, (B), by carbonylation of Rh{sup 3+}/NaY at 373-423 K. The coordination of Rh atoms (coordination number and bond length of Rh-Rh and Rh-CO bonds) and the C-O stretching modes of (A) are similar to those of crystalline Rh{sub 6}(CO){sub 16}. The new carbonyl cluster is suggested to be an isomer of (A), Rh{sub 6}(CO){sub 12}({mu}{sub 2}-CO){sub 4}, which is transformed into Rh{sub 6}(CO){sub 12}({mu}{sub 3}-CO){sub 4} at temperatures higher than 423 K.

Detailed analyses of Cu K-edge x-ray-absorption near-edge structure (XANES) of electron-doped and hole-doped Cu-based oxides with several Ce/Sr substitution rates, ${\mathrm{Nd}}_{2\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Ce}}_{\mathrm{x}}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{y}}$ and ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Sr}}_{\mathrm{x}}$${\mathrm{CuO}}_{4}$ have revealed that each Ce/Sr substitution has an effect on \ensuremath{\sim}4--5 Cu sites and that an additional electron or hole supplied with the substitution is distributed mainly to \ensuremath{\sim}4--5 [${\mathrm{CuO}}_{2}$] units, yielding ``impurity (localized) states.'' When x=0.15 the ``impurity states'' amount to \ensuremath{\sim}60--75 % of the whole [${\mathrm{CuO}}_{2}$] units; the interaction and superposition among the localized states are caused to produce bands like Fermi-liquid states. The substitution causes substantial and a little change in the XANES spectra of Nd-Ce-Cu-O and La-Sr-Cu-O, respectively. This means that the electron doping takes place mainly at the Cu site of [${\mathrm{CuO}}_{2}$] in Nd-Ce-Cu-O and that the hole doping in La-Sr-Cu-O takes place mainly at the oxygen site. In the ``unreduced'' Nd-Ce-Cu-O samples no monovalent species but rather divalent species with relatively large 3${d}^{10}$ contributions are found. In the ``reduced'' and superconducting Nd-Ce-Cu-O sample (x=0.15), ${\mathrm{Cu}}_{2}$O-like monovalent species are found but probably correspond to segregated impurity phases. The essential effect of the reduction to induce the superconductivity in Nd-Ce-Cu-O (x\ensuremath{\sim}0.15) has not yet been revealed.

SF4 has a pseudo-trigonal bipyramidal (C2v) structure with a ligand missing at one of the equatorial sites (S-F bond lengths: R(ax) > R(eq)) and an approximate electronic structure of S4+[(3s)2(3p)0]·(F−)4 with unoccupied S 3pσ orbitals of a1, b1(ax) and b2(eq) symmetry. Contrary to an empirical relationship between bond lengths and σ resonance energies, ab initio Δ SCF calculations for the core-to-valence bound-state resonances predict the ordering b(eq) < a1 < b (ax), indicating that the bond angle effect is dominant in SF4. The bond-angle dependence is discussed qualitatively in terms of crystal field theory and Walsh diagrams. The bond-length and bond-angle dependence are discussed quantitatively via the ab initio calculations.

Adsorption of NO on the Rh(111) surface has been studied in the monolayer, bilayer, and multilayer regimes with near edge x-ray absorption fine structure (NEXAFS) spectroscopy. NO dimer layers are formed on a chemisorbed monomer layer. The polarization dependence in the NEXAFS spectra of the dimer components has contradicted the previous assignments. To determine the structure of the NO dimer layers from the polarization analysis of the NEXAFS spectra, ab initio configuration interaction calculations have been carried out for some low-lying core excited states of the weakly bound NO dimer with cis-ONNO planar geometry. It is revealed that the NO dimers in the multilayer are standing with the N–N bond perpendicular to the surface, while in the second layer they are rather lying on the first monomer layer.

Autoionization dynamics of core-valence doubly excited states in ${\mathrm{N}}_{2}$ is studied by measuring angular dependence and photon energy evolution of inner-shell photoelectron spectra. The anisotropic electron emissions in the autoionization are interpreted in terms of symmetries of the doubly excited states. The autoionization features in the photoelectron spectra demonstrate clearly the electronic decay closely related to nuclear dynamics in the femtosecond regime. A nonadiabatic picture is required to describe the autoionization of a Rydberg-type doubly excited state.

The electronic states of chemically doped DNA polynucleotides [poly(dG)-poly(dC)] have been studied by photoelectron spectroscopy, x-ray absorption spectroscopy, and Raman spectroscopy, in order to understand the charge conduction mechanism of this material. Upon iodine doping (i.e., hole doping), we clearly observed radical cation formation on DNA bases, and the appearance of additional occupied and unoccupied electronic states within the band gap of poly(dG)-poly(dC). Referring to the analogous studies for $\ensuremath{\pi}$-conjugated conductive polymers, we point out that the charges induced by iodine doping and their derived electronic states are important origins of the hole-conductive electrical properties of poly(dG)-poly(dC).

Ab initio calculations are applied to the inner‐shell ionizations and excitations of molecular pyridine clusters. We found theoretically that the C 1s → π* transition is red shift while the N 1s → π* transition is blue shifted. The red shift and blue shift increase with increasing cluster size. The ground state geometries of pyridine dimers and trimers are electrostatically stabilized with the molecular dipole anti‐parallel to each other. The physical origin of the blue shifts in the N 1s regime is essentially ascribed to electrostatic interactions.

A 750 MeV synchrotron light source, UVSOR‐II, is routinely operated for users with emittance of 27 nm‐rad, which is the world smallest among the operational synchrotron light sources of relatively low energy below 1 GeV. Eight bending magnets and three undulators provide synchrotron light to totally 13 beam‐lines. Two of the undulators are of in‐vacuum type and another is of variable polarization type. A high performance monochromator for the beam‐line, BL3U, and a high‐resolution photoelectron energy analyzer for the end station at BL5U have been successfully installed, both of which utilize undulator radiation. The IR beam‐line, BL6B has been upgraded by introducing a so‐called magic mirror as the first mirrors and the world‐highest intensity has been successfully achieved. Fourth undulator of variable polarization type and its beam‐line are under construction. The energy upgrade of the injector is in progress, to realize the top‐up operation within a few years. The wavelength of the free electron laser has come into the deep UV region, thanks to the low emittance of the ring. Some users’ experiments are in progress. A Ti:Sa laser for the laser‐bunch slicing experiments was installed. Intense coherent terahertz radiation produced by the laser e‐beam interaction has been successfully detected.

Nature Physics 8, 135–138 (2012); published online 4 December 2011; corrected after print 19 November 2015. In the version of this Letter originally published the state with Emin = 23 eV was mislabelled throughout and should have been labelled 12ϕg. This has been corrected in the online versions 19 November 2015.

The core-to-sigma* excited state is repulsive for the bond elongation; on the other hand, the core ionized state and the core-to-pi* state are bound and the core-to-Rydberg states are almost parallel to the potential energy curve of the core ionized state. Thus, the core-electron excitation to the unoccupied sigma* orbital can be mixed with the one-electron Rydberg or continuum orbital, as dependent on the bond distance, and even with the unoccupied pi* orbital in some cases. Within the framework of one-electron picture, we show sigma* orbitals mixed with Rydberg character in the 1s excitation of O2 and CH3F, and Rydberg orbitals mixed with valence character in the 1s excitation of CH4, CO2, and N2O.

Kr 3d ionization energies of small, variable size krypton clusters are investigated by photoelectron spectroscopy, where the size regime of clusters with an average size N< or =30 is studied. Characteristic shifts in Kr 3d ionization energies to lower binding energies are found compared to the bare atom. These are also different from those of large krypton clusters. Moreover, we find evidence for photoionization of the krypton dimer. Its 3d ionization energy is barely shifted relative to the atomic value. Results from model calculations considering different isomers and cluster sizes as well as defect sites give evidence that the experimental results can be related to photoionization from different surface sites in variable size krypton clusters. This can be related to site-specific photoemission in small Kr clusters. The results are compared to size effects in Kr 3d near-edge features of variable size Kr clusters as well as recent results on Kr 3d photoionization of large Kr clusters.

The electronic structure of bases in DNA duplexes was investigated by resonant photoemission spectroscopy near the Fermi level, in order to specify charge migration mechanisms. We observed a kinetic energy shift of N-KLL Auger electrons and an intensity enhancement of valence electrons on the resonant photoemission spectra for both poly(dG).poly(dC) and poly(dA).poly(dT) DNAs. These directly show the localized unoccupied states of the bases. We conclude that the charge hopping model is pertinent for electric conduction in a DNA duplex, when electrons pass through the unoccupied states.

A soft x‐ray undulator beamline and an x‐ray emission spectrometer have been designed for soft x‐ray emission studies. The beamline has a varied‐line‐spacing plane grating monochromator, which enables the energy resolution over 104 with a beam size down to 10 × 60 μm2. The x‐ray emission spectrometer has a Wolter type I mirror, a free‐standing transmission grating, and a back‐illuminated CCD. A high collection angle up to 1.5 × 10−3 sr is achieved by utilizing the Wolter mirror as a prefocusing system. The CCD is mounted at 1400 mm downstream of the grating on a Rowland torus mount. Diffracted x‐rays are detected in the normal incidence geometry, resulting in high detection efficiency. The energy resolution is limited by the figure errors of the optical elements and the spatial resolution of the detector.

High-resolution photoion yield spectra of N 2 are measured near the K-shell ionization threshold. Previously unresolved multiple excitations are distinguished in the Σ- and Π-symmetry-resolved spectra, which were obtainedfrom the ion yield spectra recorded at 0° and 90° relative to the polarization direction. The three 1 Π u and two 1 Σ + u doubly excited states are clearly identified. Furthermore, a weak Π-symmetry feature just at the σ*-shape resonance position (∼419 eV) is definitely resolved and assigned to the lowest 1 Π u triple excitation with the help of quantum chemical calculations.

In order to investigate local structures of electrolytes in electrochemical reactions under the same scan rate as a typical value 100 mV/s in cyclic voltammetry (CV), we have developed an in operando observation system for electrochemical reactions by soft X-ray absorption spectroscopy (XAS) with a potential modulation method. XAS spectra of electrolytes are measured by using a transmission-type liquid flow cell with built-in electrodes. The electrode potential is swept with a scan rate of 100 mV/s at a fixed photon energy, and soft X-ray absorption coefficients at different potentials are measured at the same time. By repeating the potential modulation at each fixed photon energy, it is possible to measure XAS of electrochemical reaction at the same scan rate as in CV. We have demonstrated successful measurement of the Fe L-edge XAS spectra of aqueous iron sulfate solutions and of the change in valence of Fe ions at different potentials in the Fe redox reaction. The mechanism of these Fe redox processes is discussed by correlating the XAS results with those at different scan rates.

Efforts have been made to elucidate the origin of d(0) magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defects are present at the O sites than at the Zn sites. Specifically, the results of O K-edge scanning transmission X-ray microscopy (STXM) and the corresponding X-ray-absorption near-edge structure (XANES) spectroscopy demonstrated that the impurity (non-stoichiometric) region in ZnO NCs contains a greater defect population than the thick region. The intensity of O K-edge STXM-XANES in the impurity region is more predominant in ZnO NCs than in NWs. The increase in the unoccupied (occupied) density of states at/above (at/below) the conduction-band minimum (valence-band maximum) or the Fermi level is related to the population of defects at the O sites, as revealed by comparing the ZnO NCs to the NWs. The results of O K-edge and Zn L3,2-edge X-ray magnetic circular dichroism demonstrated that the origin of magnetization is attributable to the O 2p orbitals rather than the Zn d orbitals. Further, the local density approximation (LDA) + U verified that vacancies in the form of dangling or unpaired 2p states (due to Zn vacancies) induced a significant local spin moment in the nearest-neighboring O atoms to the defect center, which was determined from the uneven local spin density by analyzing the partial density of states of O 2p in ZnO.

High-resolution Auger spectroscopy applied under resonant Auger Raman conditions is shown to be a powerful tool for characterizing complex potential energy surfaces in core-excited systems. Using the example of Nt 1s–1*2 resonant Auger transition in nitrous oxide we emphasize the interplay between the nuclear motion and the electronic decay. We show how the choice of excitation energy allows selection of core-excited species of different geometries. The nuclear dynamics of these species are mapped by measuring the resonant Auger decay spectra. In addition to the changes in vibrational structure observed for the resonant Auger decay spectra, a strong influence of nuclear motion on the electronic decay is revealed, inducing the so-called "dynamical Auger emission." The experimental results are supported by ab initio quantum chemical calculations restricted to a linear geometry of the core-excited state.

Construction of a scanning transmission x-ray microscope (STXM) beamline is in progress at UVSOR (Okazaki, Japan). To obtain high brilliance with high resolving power for the incident x-rays, the combination of an in-vacuum undulator and a Monk-Gillieson mounting monochromator with a varied line spacing plane grating was adopted. Resolving power, spectrum and size of the incident x-rays of the beamline were discussed through simulations Then the photon flux at a sample of ~108 photons/s at the resolving power of 5,000 in the photon energy range from 100 to 700 eV is expected. As the first results, spectrum of calcium in chalk is shown.

Polarization-dependent resonant inelastic x-ray scattering is demonstrated here for liquid acetonitrile, acetone and dimethyl sulfoxide, using the liquid micro-jet technique. Selective excitation to an unoccupied orbital with a specific symmetry at the K-edge x-ray absorption of liquid samples determines the polarization-dependent emission of the occupied states. Considering the well-defined unoccupied molecular orbital configuration and utilizing the results of ab initio molecular orbital calculations, the polarization-dependent anisotropy in resonant inelastic soft x-ray scattering is discussed in a membrane-free configuration.

Carbon nanotube (CNT)/n-type SiC heterojunctions were formed by surface decomposition of 6H-SiC(0001), where each CNT directly bonded to SiC crystal at the interface without any interlayer. Through heating temperature and heating time, the CNT length could be controlled up to 4 µm. For the sample with CNTs of 180 and 230 nm in thickness, distinct rectifying behavior was observed in the current–voltage measurements, with the forward direction observed at positively biased CNTs. When the CNT length was 1500 nm, the leakage current was increased. From cross-sectional transmission electron microscopy (TEM) observations, we conclude that the increase of the leakage current was due to the deterioration of crystalline quality of CNTs near the interface between CNTs and SiC, which was caused by the obstruction of the desorption of Si atoms by the lengthening of CNTs.

The structures of mixed argon-nitrogen clusters of different compositions are investigated by analyzing core level shifts and relative intensities of surface and bulk sites in the Ar 2p(3/2) regime in soft X-ray photoelectron spectroscopy. These structures are confirmed by core level shift calculations taking induced dipole interactions into account, in which several model structures of the mixed clusters are considered by Monte Carlo simulations. These results suggest that the mixed argon-nitrogen clusters show partial core-shell structures, where an argon core is partially covered by nitrogen molecules.

Born–Oppenheimer and Franck–Condon approximations are two major concepts in the interpretation of electronic excitations and modeling of spectroscopic data in the gas and condensed phases. We r ...

Energy band alignment at the interface between carbon nanotubes (CNTs) and n-type 6H-SiC formed by the surface decomposition of SiC was investigated using high-resolution photoelectron spectroscopy (PES). Valence band spectra of the CNT films showed a Fermi edge, indicating metallic character. PES results revealed that a Schottky barrier was formed at the interface and the barrier height was 1.38 eV. Current-voltage measurements of the interface showed rectifying behavior, which was consistent with the PES results.

Ce:LuLiF4 is evaluated as a fast scintillator using a storage ring free-electron laser operating in the deep-ultraviolet region. The relatively flat spectral response across its absorption bands makes this material an attractive scintillator for various excitation sources. Its decay time is acceptable for ignition timing in fast-ignition, inertial confinement nuclear fusion using laser. This report is the first systematic study on Ce:LuLiF4 as a scintillator, wherein the storage ring free-electron laser is also shown as a powerful tool for material survey.

Oxygen K-absorption spectra were measured for La-, Y-, and Nd-system high-Tc superconductors. The spectrum of insulator for La- and Y-systems has a small structure about 1 eV above the absorption edge, being assigned to the Cu3d10 state. Hole-doping produces a new structure just at the absorption edge, whose intensity increases with hole concentration. On the other hand, the intensity of the Cu3d10 state gradually decreases. This indicates that the hole-doping brings about a transfer of weight of electronic states from the Cu3d10 states to the mid-gap states at the Fermi level. No discontinuous change was observed in the spectrum between the superconductor and the normal metal for La-system, suggesting that the electronic structure of the high-Tc superconductor is essentially the same as that of normal metal. Oxygen K-absorption spectrum of Nd-system exhibits almost no change against Ce doping, suggesting that the O2p orbital is not directly involved in the high-Tc mechanism for the electron-doped superconductor.

Core excitation from terminal oxygen O$_T$ in O$_3$ is shown to be an excitation from a localized core orbital to a localized valence orbital. The valence orbital is localized to one of the two equivalent chemical bonds. We experimentally demonstrate this with the Auger Doppler effect which is observable when O$_3$ is core-excited to the highly dissociative O$_{T}$1s$^{-1}$7a$_1^1$ state. Auger electrons emitted from the atomic oxygen fragment carry information about the molecular orientation relative to the electromagnetic field vector at the moment of excitation. The data together with analytical functions for the electron-peak profiles give clear evidence that the preferred molecular orientation for excitation only depends on the orientation of one bond, not on the total molecular orientation. The localization of the valence orbital "7a$_1$" is caused by mixing of the valence orbital "5b$_2$" through vibronic coupling of anti-symmetric stretching mode with b$_2$-symmetry. To the best of our knowledge, it is the first discussion of the localization of a core excitation of O$_3$. This result explains the success of the widely used assumption of localized core excitation in adsorbates and large molecules.

We have investigated the feasibility of an ab initio polyatomic R-matrix/MQDT (multichannel quantum defect theory) method using Gaussian type basis functions for bound and continuum states to analyze the near edge feature of molecules. Test molecules here are N2, C2H2, and NO. The R-matrix/MQDT method is revealed to be indispensable for the Rydberg states with higher quantum numbers and continuum states, none of which can be described by using Gaussian type functions in the outer region from an appropriate boundary. The close-coupling calculation augmented with the correlation term, which is carried out for the inner region, is powerful to describe the valence states and the interchannel coupling in several core-ionized states.

Cluster size effects in core excitons below the N 1s ionization energy of nitrogen clusters are reported in the energy regime 405-410 eV. These results are compared to the molecular Rydberg states as well as the corresponding bulk excitons of condensed nitrogen. The experimental results are assigned using ab initio calculations. It is found that the lowest excitons (N 1s-->3ssigma and N 1s-->3ppi) are blueshifted relative to the molecular Rydberg transitions, whereas others (N 1s-->3dpi and N 1s-->4ppi) show a redshift. Results from ab initio calculations on (N(2))(13) clearly indicate that the molecular orientation within a cluster is critical to the spectral shift, where bulk sites as well as inner- and outer-surface sites are characterized by different inner-shell absorption energies. These results are compared to the experimental spectra as well as previous work on site-selectively excited atomic van der Waals clusters, providing an improved spectral assignment of core exciton states in weakly bound molecular clusters and the corresponding condensed phase.

We have characterized the material which has been prepared by the heat treatment of the mixture of 1,2,4,5-tetracyanobenzene (TCNB) and Cu powder at 5 GPa and 500 °C. Dark gray material which incorporates Cu showed high conductivity ( σ RT = 1 Scm −1 ) at room temperature. Although the X-ray diffraction and 13 C NMR indicate the inhomogeneous structure, EXAFS and ESR suggest the local structure which is expected in the Poly-CuPc sheet polymer.