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X-ray absorption spectroscopy (XAS) has grown as one of the essential tools to analyze electronic and geometric structure of a target element in chemistry over the course of a half-century. X-ray e...

There are very great differences between the non-resonant U M subshell X-ray Emission Spectra of Uranium Dioxide generated with low and high-energy excitation. These different spectra are each supported by theoretical constructs. It will be shown that the differences between these experimental spectra can be reconciled and the utility of both theoretical approaches confirmed, including the use of FEFF in the low energy and high-energy regimes.

An extensive experimental and theoretical study of the Kα and Kβ high-resolution X-ray emission spectroscopy (XES) of sulfur-bearing systems is presented. This study encompasses a wide range of organic and inorganic compounds, including numerous experimental spectra from both prior published work and new measurements. Employing a linear-response time-dependent density functional theory (LR-TDDFT) approach, strong quantitative agreement is found in the calculation of energy shifts of the core-to-core Kα as well as the full range of spectral features in the valence-to-core Kβ spectrum. The ability to accurately calculate the sulfur Kα energy shift supports the use of sulfur Kα XES as a bulk-sensitive tool for assessing sulfur speciation. The fine structure of the sulfur Kβ spectrum, in conjunction with the theoretical results, is shown to be sensitive to the local electronic structure including effects of symmetry, ligand type and number, and, in the case of organosulfur compounds, to the nature of the bonded organic moiety. This agreement between theory and experiment, augmented by the potential for high-access XES measurements with the latest generation of laboratory-based spectrometers, demonstrates the possibility of broad analytical use of XES for sulfur and nearby third-row elements. The effective solution of the forward problem, i.e., successful prediction of detailed spectra from known molecular structure, also suggests future use of supervised machine learning approaches to experimental inference, as has seen recent interest for interpretation of X-ray absorption near-edge structure (XANES).

Inorganic chemistry 59(12), 8272 - 8283 (2020). doi:10.1021/acs.inorgchem.0c00663, Ruthenium 4d-to-2p X-ray emission spectroscopy (XES) was systematically explored for a series of Ru$^{2+}$ and Ru$^{3+}$ species. Complementary density functional theory calculations were utilized to allow for a detailed assignment of the experimental spectra. The studied complexes have a range of different coordination spheres, which allows the influence of the ligand donor/acceptor properties on the spectra to be assessed. Similarly, the contributions of the site symmetry and the oxidation state of the metal were analyzed. Because the 4d-to-2p emission lines are dipole-allowed, the spectral features are intense. Furthermore, in contrast with K- or L-edge X-ray absorption of 4d transition metals, which probe the unoccupied levels, the observed 4p-to-2p XES arises from electrons in filled-ligand- and filled-metal-based orbitals, thus providing simultaneous access to the ligand and metal contributions to bonding. As such, 4d-to-2p XES should be a promising tool for the study of a wide range of 4d transition-metal compounds., Published by American Chemical Society, Washington, DC

International audience; Hard x-ray emission spectroscopy (XES) has been used to study buried layers and interfaces in a Fe/Si periodic multilayer. Until now, buried layers could be studied using the XES in the soft x-ray range. Here we extend the methodology to study the buried interfaces in hard x-ray region (photon energy ≥ 5 keV). We report the formation of FeSi2 at all the interfaces with thicknesses of 1.4 nm. X-ray reflectivity measurements enable us to deduce the structure and thickness of the multilayer stack, thereby confirming the presence of FeSi2.

A genetic algorithm (GA) is developed and applied to make proper connections of final-state potential-energy surfaces and X-ray emission (XES) cross sections between steps in the time-propagation of H-bonded systems after a core–hole is created. We show that this modification results in significantly improved resolution of spectral features in XES with the semiclassical Kramers–Heisenberg approach which takes into account important interference effects. We demonstrate the effects on a water pentamer model as well as on two 17-molecules water clusters representing, respectively, tetrahedral (D2A2) and asymmetric (D1A1) H-bonding environments. For D2A2, the applied procedure improves significantly the obtained intensities, whereas for D1A1 the effects are smaller due to milder dynamics during the core–hole life-time as only one hydrogen is involved. We reinvestigate XES for liquid ethanol and, by properly disentangling the relevant states in the dense manifold of states using the GA, now resolve the important 3a′′ state as a peak rather than a shoulder. Furthermore, by applying the SpecSwap-RMC procedure, we reweigh the distribution of structures in the sampling of the liquid to fit to experiment and estimate the ratio between the main anti and gauche conformers in the liquid at room temperature. This combination of techniques will be generally applicable to challenging problems in liquid-phase spectroscopy.

В работе методами растровой электронной микроскопии и ультрамягкойрентгеновской эмиссионной спектроскопии были проведены исследования особенностейформирования многослойных структур пористого кремния и установлено влияние изменения плотности тока при электрохимическом травлении монокристаллических пластин кремния на фазовый состав поверхностных слоев сформированной пористой структуры. ЛИТЕРАТУРА1. Moshnikov V., Gracheva I., Lenshin A., Spivak Yu. Porous silicon with embedded metal oxides for gassensing applications // Journal of Non-Crystalline Solids, 2012 v. 358(3), pp. 590–595. DOI: https://doi.org/10.1016/j.jnoncrysol.2011.10.0172. Pacholski C. Photonic crystal sensors based on porous silicon // Sensors, 2013, v. 13(4), pp. 4694–4713.DOI: https://doi.org/10.3390/s1304046943. Harraz F. Porous silicon chemical sensors and biosensors: A review // Sensors and Actuators B, 2014,v. 202, pp. 897–912. DOI: https://doi.org/10.1016/j.snb.2014.06.0484. 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DOI: https://doi.org/10.1016/0040-6090(95)08036-813. Caballero-Hernandez J., Godinho V., Lacroix B., Haro M., Jamon D., Fernandez A. Fabrication of opticalmultilayer devices from porous silicon coatings with closed porosity by magnetron sputtering // ACS Appl.Mater. Interfaces, 2015, v. 7(25), pp. 13889–13897. DOI: https://doi.org/10.1021/acsami.5b0235614. Terekhov V, Kashkarov V, Manukovskii E., Schukarev A., Domashevskaya E. Determination of thephase composition of surface layers of porous silicon by ultrasoft X-ray spectroscopy and X-ray photoelectronspectroscopy techniques // J. Electron. Spectrosc., 2001, v. 114–116, pp. 895–900. DOI: https://doi.org/10.1016/s0368-2048(00)00393-515. Shulakov A. X-ray emission depth-resolved spectroscopy for investigation of nanolayers. // Journalof Structural Chemistry, Supplement, 2011, v. 52(S1), pp. 1–12. DOI: https://doi.org/10.1134/s002247661107001816. Mashin A., Khokhlov A., Mashin N., Domashevskaya E., Terekhov V. 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We present a comparative study that focuses on the variability of post-deposition treatments (NaF-PDT and KF-PDT) and their impact on the chemical and electronic structure of chalcopyrite thin film...

Valence-to-Core (VtC) X-ray emission spectroscopy (XES) was used to directly detect the presence of an O-O bond in a complex comprising the [CuII 2 (μ-η2 :η2 -O2 )]2+ core relative to its isomer with a cleaved O-O bond having a [CuIII 2 (μ-O)2 ]2+ unit. The experimental studies are complemented by DFT calculations, which show that the unique VtC XES feature of the [CuII 2 (μ-η2 :η2 -O2 )]2+ core corresponds to the copper stabilized in-plane 2p π peroxo molecular orbital. These calculations illustrate the sensitivity of VtC XES for probing the extent of O-O bond activation in μ-η2 :η2 -O2 species and highlight the potential of this method for time-resolved studies of reaction mechanisms.

A series of β-diketiminate Ni-NO complexes with a range of NO binding modes and oxidation states were studied by X-ray emission spectroscopy (XES). The results demonstrate that XES can directly probe and distinguish end-on vs side-on NO coordination modes as well as one-electron NO reduction. Density functional theory (DFT) calculations show that the transition from the NO 2s2s σ* orbital has higher intensity for end-on NO coordination than for side-on NO coordination, whereas the 2s2s σ orbital has lower intensity. XES calculations in which the Ni-N-O bond angle was fixed over the range from 80° to 176° suggest that differences in NO coordination angles of ∼10° could be experimentally distinguished. Calculations of Cu nitrite reductase (NiR) demonstrate the utility of XES for characterizing NO intermediates in metalloenzymes. This work shows the capability of XES to distinguish NO coordination modes and oxidation states at Ni and highlights applications in quantifying small molecule activation in enzymes.

A combination of X-ray photoelectron/Auger electron spectroscopy and soft X-ray emission spectroscopy has been employed to investigate the impact of different alkali postdeposition treatments (PDTs...

We present valence-to-core x-ray emission spectroscopy of Ti, TiO and TiO2 by means of a double crystal von Hamos spectrometer based on full-cylinder highly-annealed pyrolytic graphite mosaic crystals. We demonstrate that, using a double crystal configuration, an energy resolution of E/ΔE ≈ 2700 can be achieved in a compact setup using cylindrically curved optics with a radius of curvature of 50 mm. The stated energy resolution proved to be high enough to identify and determine chemical shifts of the Kβ2,5 and Kβ" emission lines of both oxides. The experimental results are supported by calculations with the ab initio package OCEAN and compared to literature values.

X-ray emission spectra reveal that under pressure conditions of Earth's lower mantle, the compaction mechanism in amorphous germanium dioxide on the atomic scale is similar to that of its crystalline form.

The Zn 1s valence-to-core (VtC) X-ray emission spectra of seven ionic liquids have been measured experimentally and simulated on the basis of time-dependent density-functional theory (TDDFT) calculations. Six of the\ud ionic liquids were made by mixing [C8C1Im]X and Zn(II)X2\ud at three different ZnX2 mole fractions (0.33, 0.50, or 0.67) for X = Cl or Br, and a further ionic liquid was made by mixing [P6,6,6,14]Cl and a mole fraction of ZnCl2 of 0.33. Calculations were performed for the [ZnX4] 2−, [Zn2X6] 2−, and [Zn4X10] 2− ions to capture the expected metal complex speciation. The VtC emission spectra showed three bands arising from singleelectron processes that can be assigned to emission from ligand p-type orbitals, zinc d-orbitals, and ligand s-type orbitals. For all seven ionic liquids, the highest occupied molecular orbital arises from the ligand p orbitals, and the spectra for the different size metal complexes for the same X were found to be very similar, in terms of both relative peak intensities and peak energies. For both experiments and TDDFT calculations, there was an energy difference of 0.5 eV between the Cl-based and Br-based metal complexes for the ligand s and p orbitals, while the Zn 3d orbital energies were relatively unaffected by the identity of the ligand. The TDDFT calculations find that for the ions with symmetrically equivalent zinc atoms ([Zn2X6] 2− and [Zn4X10] 2−), the most appropriate core-ionized reference state has a core-hole that is localized on a single zinc atom. In this framework, the spectra for the larger ions can be viewed as a sum of spectra for the tetrahedral complex with a single zinc atom with small variations in the structure of the coordinating ligands. Because the spectra are relatively insensitive to small changes in the geometry of the ligands, this is consistent with the small variation in the spectra measured in the experiment.

The electronic structure and features of interatomic interactions providing the Si–O–C6H5 bonds in H4-nSi(OC6H5)n (n = 1–4) were studied by a combined analysis of the X-ray emission and photoelectron spectroscopic data and the results of quantum-chemical calculations. Theoretical calculations were carried out using the density functional theory. The distributions of the density of states were constructed, the correlation energy diagrams were presented, and the main types of interatomic interactions in phenoxysilanes were revealed.

The structural, electronic, and magnetic properties of materials under high pressure are of fundamental interest in physics, chemistry, materials science, and earth sciences. Among several hard X-ray-based techniques, X-ray emission spectroscopy (XES) provides a powerful tool to probe element-specific information for understanding the electronic and magnetic properties of materials under high pressure. Here, we discuss on the particular requirements and instrumentation used in high pressure XES experiments. We then present several examples to illustrate the recent progress in high pressure XES studies at the Advanced Photon Source, followed by an outlook toward future development in high pressure XES.

The first observation of Intermediate Coupling effects in the occupied 5f states has been made using x-ray Emission Spectroscopy (XES). In the past, the impact of Intermediate Coupling of the 5f states in actinides has long been observed and quantified, using x-ray Absorption Spectroscopy (XAS) to probe the unoccupied 5f states, providing great insight into the enigma of 5f electronic structure. However, no measure of its effects in the occupied states had been reported before this. Moreover, because the 5f occupied states in UF4 are almost completely of 5f5/2 character, the observed effect in XES is twice that in XAS for UF4.

O Tecnécio-99m (99mTc), gerado a partir do decaimento do Molibdênio-99 (99Mo), é o radionuclídeo mais conveniente para a execução de procedimentos de diagnósticos médicos, devido à sua emissão gama bem característica e de fácil detecção. O método utilizado para produzir 99Mo é através da fissão do 235U incorporado nos chamados alvos de irradiação. Duas rotas estão sendo desenvolvidas para a produção do 99Mo por fissão para o Reator Multipropósito Brasileiro (RMB), ambas utilizando urânio de baixo enriquecimento (LEU): 1) A primeira a dissolução básica, que é baseada na tecnologia de alvos de dispersão UAlx-Al. 2) A segunda emprega a dissolução ácida de alvos de folhas finas de urânio metálico. A principal vantagem dos alvos de folha fina de urânio metálico sobre os alvos de dispersão UAlx-Al é a alta densidade do urânio metálico. Com o intuito de compreender e otimizar o processo de fabricação de alvos de folhas finas foi realizado um estudo da fusão do urânio metálico, laminação de folhas finas, caracterização microestrutural e montagem dos alvos, definindo assim, os procedimentos específicos para a produção desse tipo de alvo com as características dos alvos fabricados internacionalmente. Os resultados obtidos mostraram que o processo de fabricação dos lingotes e de lâminas de urânio metálico por meio de laminação a quente possibilitaram a obtenção de lâminas com espessura entre 250 e 300 μm. O processo de laminação a frio possibilitou a obtenção de folhas finas com espessura de ±125 μm que atende à especificação internacional. O uso de óxido de alumínio como material para prevenir caldeamento do tablete de urânio mostrou-se eficiente, substituindo com vantagens o uso de óxido de ítrio. A microestrutura após o tratamento térmico apresentou grãos equiaxiais pequenos, e a realização de um resfriamento rápido de 5 minutos após o tratamento térmico foi suficiente para se eliminar a textura da folha fina de urânio metálico. O processo de montagem das folhas finas no alvo tubular foi realizado por pré-conformação da folha fina, facilitando a montagem. O processo de consolidação do alvo foi realizado por expansão por tração e a folga após a consolidação (\"gap de ar\") mostrou-satisfatória. As dimensões finais dos alvos tubulares atenderam à especificação internacional. Technetium-99m (99mTc) is generated from the decay of Molybdenum-99 (99Mo). This element is the most convenient radionuclide for application in medical diagnostic procedures, once that its gamma emission is well known and of easily detected. The method used to produce 99Mo is through fission of the 235U embedded in so-called irradiation targets. Two routes are being developed for the production of 99Mo per fission to the Brazilian Multipurpose Reactor (RMB), both using low enriched uranium (LEU): 1) The first basic dissolution, which is based on the technology of dispersion targets UAlx-Al. 2) The second employs the acidic dissolution of thin sheet targets of metallic uranium. The main advantage of uranium metal foil targets on the UAlx-Al dispersion targets is the high density of metallic uranium. In order to understand and optimize the process of manufacturing thin sheet targets, about the fusion of metallic uranium, thin sheet lamination, microstructural characterization and assembly of the target was carried out. Therefore the specific procedures for the production of this type of target with the characteristics of the targets manufactured internationally could be defined. The results showed that the process of manufacturing ingots and sheets of metallic uranium by hot rolling allows obtaining sheets with thickness between 250 and 300 μm. The cold rolling process allows obtaining thin sheets with a thickness of ± 125 μm which are in accordance with the international specification. The use of aluminum oxide as a material to prevent uranium tablet firing proved to be efficient, replacing with advantage the use of yttrium oxide. The microstructure after the heat treatment showed small equiaxial grains. A fast cooling of 5 minutes after the heat treatment was enough to eliminate the texture of the thin sheet of metallic uranium. The process of assembling the thin sheets in the tubular target was performed by preforming the thin sheet, facilitating the assembly. The process of consolidating the target was performed by tensile expansion and the clearance after consolidation (\"air gap\") was satisfactory. The final dimensions of the tubular targets have met the international specification.

Proton transfer reactions are of central importance to a wide variety of biochemical processes, though determining proton location and monitoring proton transfers in biological systems is often extremely challenging. Herein, we use two-color valence-to-core x-ray emission spectroscopy (VtC XES) to identify protonation events across three oxidation states of the O(2)-activating, radical-initiating manganese-iron heterodinuclear cofactor in a class I-c ribonucleotide reductase. This is the first application of VtC XES to an enzyme intermediate and the first simultaneous measurement of two-color VtC spectra. In contrast to more conventional methods of assessing protonation state, VtC XES is a more direct probe applicable to a wide range of metalloenzyme systems. These data, coupled to insight provided by DFT calculations, allow the inorganic cores of the Mn(IV)Fe(IV) and Mn(IV)Fe(III) states of the enzyme to be assigned as Mn(IV)(μ-O)(2)Fe(IV) and Mn(IV)(μ-O)( μ-OH)Fe(III), respectively.

The potential of valence to core Al X-ray emission spectroscopy to determine aluminum distribution in ferrierite zeolites was investigated. The recorded emission spectra of four samples prepared with different structure directing agents exhibit slight variations in the position of the main emission peak and the intensity of its low energy shoulder. Theoretical calculations indicate that an increased intensity of the Kβx shoulder in the Al emission spectra can be linked to a predominant occupation of the T3 site by a single aluminum atom. This study thus suggests that valence to core X-ray emission spectroscopy can be applied to help determine the occupation of aluminum at crystallographic T-sites in zeolites.

We report measurement of the valence-to-core (VTC) region of the K-shell x-ray emission spectra from several Zn and Fe inorganic compounds, and their critical comparison with several existing theoretical treatments. We find generally good agreement between the respective theories and experiment, and in particular find an important admixture of dipole and quadrupole character for Zn materials that is much weaker in Fe-based systems. These results on materials whose simple crystal structures should not, a prior, pose deep challenges to theory, will prove useful in guiding the further development of DFT and time-dependent DFT methods for VTC-XES predictions and their comparison to experiment.

Double perovskites BaLaMnSbOwere synthesized by traditional ceramic methods in air as polycrystalline powders. The 0.1 ≤ x ≤ 0.2 compounds belong to the I 2/m monoclinic space group, while the perovskites with x ≥ 0.3 belong to the I 4/m tetragonal space group. The effective presence of mixtures of Mn/Mnhas been well established by X-ray Emission Spectroscopy. BaLaMnSbO(0.1 ≤ x ≤ 0.5) oxides display signs of superparamagnetism in the 40–160 K range, which arises from 3D-nanoclusters formed in regions which are rich in Mn–O–Mnsuperexchange paths originated by the antisite disorder. The analysis of the M vs H hysteresis loops shows that, as x increases, the number of 3D-nanoclusters rises and the number of magnetic ions in the 3D-nanoclusters decreases. The small 3D-nanoclusters cannot sustain magnetic order inside them and this is the reason for the absence of superparamagnetism for x = 0.6 and 0.7. The analysis of the M vs H curves also shows the presence of a weak ferromagnetism which is generated by the canting of the spins in the antiferromagnetic matrix. Neutron Powder Diffraction data reveals that there is long range antiferromagnetic ordering below ≈20 K., Financial support from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (grant to R. E. C.: PIP #11220120100360, fellowship to D. M. A.), by the Agencia Nacional de Promoción Científica y Tecnológica (grant to R. E. C.: PICT 2013-2149), by the Secretaría de Ciencia y Tecnología de la Universidad Nacional de Córdoba (SECyT-UNC) (project number 203/14). J.A.A. acknowledges the financial support of the Spanish MINECO to the project MAT2013-41099-R.

Extensive study of the electronic structure of Fe-NO complexes using a variety of spectroscopic methods was attempted to understand how iron controls the binding and release of nitric oxide. The comparable energy levels of NO π* orbitals and Fe 3d orbitals complicate the bonding interaction within Fe-NO complexes and puzzle the quantitative assignment of NO oxidation state. Enemark-Feltham notation, {Fe(NO)x}(n), was devised to circumvent this puzzle. This 40-year puzzle is revisited using valence-to-core X-ray emission spectroscopy (V2C XES) in combination with computational study. DFT calculation establishes a linear relationship between ΔE(σ2s*-σ2p) of NO and its oxidation state. V2C Fe XES study of Fe-NO complexes reveals the ΔE(σ2s*-σ2p) of NO derived from NO σ(2s)*/σ(2p)→Fe(1s) transitions and determines NO oxidation state in Fe-NO complexes. Quantitative assignment of NO oxidation state will correlate the feasible redox process of nitric oxide and Fe-nitrosylation biology.

Experimental tools capable of monitoring both atomic and electronic structure on ultrafast (femtosecond to picosecond) time scales are needed for investigating photophysical processes fundamental to light harvesting, photocatalysis, energy and data storage, and optical display technologies. Time-resolved hard x-ray (>3 keV) spectroscopies have proven valuable for these measurements due to their elemental specificity and sensitivity to geometric and electronic structures. Here, we present the first tabletop apparatus capable of performing time-resolved x-ray emission spectroscopy. The time resolution of the apparatus is better than 6 ps. By combining a compact laser-driven plasma source with a highly efficient array of microcalorimeter x-ray detectors, we are able to observe photoinduced spin changes in an archetypal polypyridyl iron complex [Fe(2,2^{′}-bipyridine)_{3}]^{2+} and accurately measure the lifetime of the quintet spin state. Our results demonstrate that ultrafast hard x-ray emission spectroscopy is no longer confined to large facilities and now can be performed in conventional laboratories with 10 times better time resolution than at synchrotrons. Our results are enabled, in part, by a 100- to 1000-fold increase in x-ray collection efficiency compared to current techniques.

XRD data on the layered vanadium-substituted copper-chromium disulfides (CuCr1−x V x S2, x = 0−0.4) are compared with the data obtained by X-ray emission and photoelectron spectroscopies.

The X-ray photoelectron and X-ray emission spectra as well as the charge state of thiacalix[4]arenes in the cone and 1,3-alternate conformations and calix[4]arene thioesters were studied. The donor ability of sulfur bridging atoms in the studied compounds was shown to be close to that in dialkyl sulfides. The internal X-ray transitions (Kα and Kβ) were described by the energy of Kohn-Sham orbitals calculated by DFT method with relaxation corrections.

Using a simplified model, we calculate resonant X-ray emission (RXE) spectra with Ce 2p to 5d excitation and Ce nl to 2p de-excitation for mixed valence Ce compounds, where nl is 3d or valence stat ...

Nonresonant X-ray emission spectroscopy was used to compare the nitrogen-rich compounds ammonium nitrate, trinitrotoluene, and cyclotrimethylene-trinitramine. They are representative of crystalline and molecular structures of special importance in industrial and military applications. The spectral signature of each substance was analyzed and correlated with features in the electronic structure of the systems. This analysis was accomplished by means of theoretical simulations of the emission spectra and a detailed examination of the molecular orbitals and densities of states. We find that the two theoretical methods used (frozen-orbital density functional theory and real-space Green's function simulations) account semiquantitatively for the observed spectra and are able to predict features arising from distinct chemical complexes. A comparison of the calculations and the data provides insight into the electronic contributions of specific molecular orbitals, as well as the features due to bandlike behavior. With some additional refinements, these methods could be used as an alternative to reference compounds.

Recently, there have been a number of claims about the nature of water as a liquid that seem to contradict traditional views. The present paper takes a close look at two of these claims—namely, that water is not the tetrahedral network that it is traditionally regarded as but a chain-like liquid, and that water is intrinsically heterogeneous by nature—and attempts to make sense of them.

The electronic structure of Mn in (Zn, Mn)O with different Mn concentrations has been investigated using resonant X-ray emission spectroscopy (RXES). The Mn L 2 , 3 RXES spectra reveal different spectral features depending on the resonant excitation energies and Mn concentrations. The surface dd excitations at about −1.9 eV of energy loss are identified in the highest Mn-doped sample. The comparison of integral intensity ratio of Mn L 2 to L 3 emission lines for these samples suggests that ferromagnetic samples have a large amount of free charge carriers, which are under consideration for the origin of ferromagnetism, with respect to antiferromagnetic ones.

The K-Edge (1s) x-ray emission spectroscopy of uranium tetrafluoride and uranium dioxide were compared to each other and to the results of a pair of earlier cluster calculations. Using a very simplified approach, it is possible to qualitatively reconstruct the main features of the x-ray emission spectra from the cluster calculation state energies and 2p percentages.