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The development of automated rapid chemistry techniques and their application for batch-wise, chromatographic separations of heavy elements in the liquid-phase are outlined. Starting in the mid-1970s with manually performed separations using pressurized liquid-chromatography techniques, this development led to the first version of the Automated Rapid Chemistry Apparatus, ARCA, in the early 1980s. After a breakthrough to a much higher level of automation and miniaturization, the new apparatus ARCA II was built in the late 1980s. Based on it, the Automated Ion-exchange separation apparatus coupled with the Detection system for Alpha spectroscopy, AIDA, became operational in the late 1990s. In the context of technical and technological advancements, this article discusses the successful application of these instruments for (i) the search for superheavy elements, (ii) cross section measurements of actinide elements produced in multi-nucleon transfer reactions with actinide targets, (iii) chemical separation and characterization of the heavy actinides mendelevium, Md, and lawrencium, Lr, and (iv) studies of the transactinide elements rutherfordium, Rf, dubnium, Db, and seaborgium, Sg. Details of the separations are outlined together with the big advancements made over time and the limitations reached. For the transactinide elements, examples are given for their observed chemical behavior; often affected by an interplay between hydrolysis and complex formation. Influenced by relativistic effects, chemical properties of these elements sometimes deviated from those of their lighter homologs in the Periodic Table. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify relevant Rf chemical species by using reversed-phase extraction chromatography with 2-thenoyltrifluoroacetone (TTA) resin as the stationary phase. Because TTA can be used to extract specific metal ions, the distribution ratios of the system enabled determination of the specific complex formation constant of Rf. We performed several experiments on chemical systems with Zr, Hf, No, and Rf, determined their adsorption coefficients, and deduced the Kd values for Rf. [ABSTRACT FROM AUTHOR]

In this work we describe a novel concept for an efficient ion extraction for laser ablation time-of-flight mass spectrometry. The concept combines a sample, placed in a chamber filled with a helium buffer gas, a conventional converging-diverging supersonic nozzle connected to this chamber at short distance behind the sample, an electrodynamic Rf-only ion funnel placed on the nozzle axis in immediate vicinity of the nozzle exit plane and a pulsed laser source (frequency-doubled Nd:YAG, 532 nm, 3 ns pulse duration; 7.6 × 10 8  W power, 10 Hz repetition rate), focused onto the sample surface to a spot diameter of 110 μm after passing through the funnel and the supersonic nozzle. The primary hot ions generated during ablation are cooled by collisions with buffer gas, accelerated into the subsonic converging part of the nozzle and finally transported through the supersonic diverging part of the nozzle into the Rf-only funnel via gas expansion. Inside funnel ions are again cooled and focused by the converging electrodes and the applied RF field towards the high vacuum stage containing the ion optics and mass analyzer. To evaluate the performance of the instrument, parametric studies were carried out. It was found that ion transmission is strongly dependent on the applied RF amplitude and frequency as well as the buffer gas pressure in the ablation region and funnel chamber. The present configuration achieves an integrated sensitivity approximately 2 orders of magnitude higher than when the ablation is carried out under high-vacuum conditions with the sample placed at the position of the ion funnel exit. The new ion guide leads to significantly longer duration of ion signals from a single laser pulse and thereby would also alleviate space charge effects. The signal profile is mostly dependent on pressure conditions in the ion source. To some extent it is also affected by the RF-operating conditions of the ion funnel. Optimizing for high transmission of low m/Q ions caused an intermediate suppression of ion signals of high m/Q isotopes and vice versa. Because the respective suppression is highest during the peak maximum of the highly abundant ions, this behavior is attributed to exceeding the space charge limit inside the ion funnel for high total ion currents. Furthermore, cluster ion abundancies and their transmission were characterized. Molecular oxide ions and water clusters were found to be the dominating molecular ions in this study. Their formation generally increased with buffer gas pressure in the ablation chamber, while otherwise transmission through the ion funnel was similarly affected by the ion funnel operation as by atomic ions of similar m/Q. Relative sensitivity coefficients were found to be generally comparable when analyzing standard reference materials of similar matrix composition with laser ablation using a wavelength of 532 nm, nanosecond laser. [ABSTRACT FROM AUTHOR]

Abstract: We present an investigation of isostructural complexes that feature unsupported direct bonds between a formally trivalent lanthanide ion (Dy3+) and either a first‐row (Fe) or a second‐row (Ru) transition metal (TM) ion. The sterically rigid, yet not too bulky ligand PyCp22− (PyCp22−=[2,6‐(CH2C5H3)2C5H3N]2−) facilitates the isolation and characterization of PyCp2Dy−FeCp(CO)2 (1; d(Dy–Fe)=2.884(2) Å) and PyCp2Dy−RuCp(CO)2 (2; d(Dy–Ru)=2.9508(5) Å). Computational and spectroscopic studies suggest strong TM→Dy bonding interactions. Both complexes exhibit field‐induced slow magnetic relaxation with effectively identical energy barriers to magnetization reversal. However, in going from Dy−Fe to Dy−Ru bonding, we observed faster magnetic relaxation at a given temperature and larger direct and Raman coefficients, which could be due to differences in the bonding and/or spin–phonon coupling contributions to magnetic relaxation. [ABSTRACT FROM AUTHOR]

The different atomic ratios of FeCo alloys with various morphologies have been prepared through a simple liquid-thermal reduction method. It is found that the atomic ratio of ferrum and cobalt has great influence on the formation of FeCo alloys. Via adjusting Fe/Co atomic ratio (3:7, 5:5, 7:3), the surface of alloy becomes smooth gradually from distinct cone structure, and the saturation of alloys have been improved with the increase of Fe proportion. The impedance matching is also related tightly with atomic ratio and the best condition can be achieved by Fe 7 Co 3 with lower dielectric constant and higher permeability. It is delighted to find that the optimal reflection loss (RL) value of Fe 7 Co 3 can reach −53.6 dB at 14.3 GHz with a thin thickness of 1.55 mm and the RL values less than −10 dB can be gained from 11.2 to 18 GHz, which covering the whole Ku-band. The excellent performance derived from strong magnetic loss and well dielectric loss guarantees it as an ideal high-frequency microwave absorbent. [ABSTRACT FROM AUTHOR]

This study presents the detailed explanation of the factors, contributing towards the absorption peaks in reflection loss spectrum of hexaferrites. Cobalt-Zirconium substituted strontium hexaferrites, synthesized using sucrose precursor sol-gel technique, were analyzed in 12.4–18 GHz frequency range. The concepts of impedance matching through quarter wavelength condition, complex thickness, dielectric phase angle and attenuation constant have been used to determine the location as well as intensity of absorption peaks. This study also demonstrates the potential application of three compositions of this series with doping content (x)==0.0, 0.6 and 0.8 as an effective microwave absorbers in Ku-frequency band. [ABSTRACT FROM AUTHOR]

We successfully observed the equilibrium state of the chemical reactions for superheavy elements on a one-atom-at-a-time scale; we investigated the time dependence of the extraction behaviour of element 104, Rf. The distribution coefficient of Rf in 9 M HCl was found to be higher than those of its homologous elements, probably due to differences in the chloride complexation of Rf. [ABSTRACT FROM AUTHOR]

The design of novel microwave absorbers in the Ku band is still challenging. The aim of this work is to report the design of a new Ku absorber based on the combination of three M-hexaferrites with the formula of BaX 0.3 Y 0.3 Cr 0.3 Fe 11.1 O 19 (XY=Co 2+ Zr 4+ , Zn 2+ Ti 4+ , Mn 2+ Ce 4+ ), 15 wt% of each in epoxy matrix. The results indicate the formation of a broadband absorber with a reflection loss (RL) lower than −10 dB over the whole bandwidth 13.75–18 GHz. It has three matching frequencies (14.2, 15.3 and 16.8 GHz) with RL (−29.2, −21.5 and −24.7 dB, respectively) at a matching thickness of only 2.5 mm. This is to be compared with the RL of the absorbers based on 45 wt% of each ferrite alone in epoxy matrix are (−15, −28.8 and −20 dB, respectively) at matching frequency of (14.15, 13.55 and 16.5 GHz) and a matching thickness of 4 mm. This favorable performance resulting from combining the three ferrites within the absorber may be attributed to the enhanced exchange coupling interactions between the three powders of distinct magnetic characteristics. [ABSTRACT FROM AUTHOR]

This article presents a novel design for a superconducting rf electron injector that incorporates energy recovery. This concept relaxes the demands of high power input couplers, improves essential beam parameters and energy efficiency and reduces the overall cost of a compact energy recovery linac machine. [ABSTRACT FROM AUTHOR]

In this work, two new and powerful chemometrics methods are applied for the modeling and prediction of the 19 F chemical shift values of some fluorinated organic compounds. The radial basis function-partial least square (RBF-PLS) and random forest (RF) are employed to construct the models to predict the 19 F chemical shifts. In this study, we didn't used from any variable selection method and RF method can be used as variable selection and modeling technique. Effects of the important parameters affecting the ability of the RF prediction power such as the number of trees (n t ) and the number of randomly selected variables to split each node (m) were investigated. The root-mean-square errors of prediction (RMSEP) for the training set and the prediction set for the RBF-PLS and RF models were 44.70, 23.86, 29.77, and 23.69, respectively. Also, the correlation coefficients of the prediction set for the RBF-PLS and RF models were 0.8684 and 0.9313, respectively. The results obtained reveal that the RF model can be used as a powerful chemometrics tool for the quantitative structure–property relationship (QSPR) studies. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a linearly polarized 2 × 2 patch array uniformly fed by a corporate substrate integrated waveguide network for Ku band is presented. Undesired main beam steering is avoided by means of a fully corporate feeding network, although grating lobes may appear due to greater separation between radiating elements. Moreover, a reduced patch separation to avoid grating lobe appearance leads to an antenna matching coefficient degradation due to the proximity of antenna discontinuities. In consequence, a tradeoff approach has been developed, achieving a measured 4.1% matching bandwidth and a measured gain of 13.27 dBi, which corresponds to an 86% radiation efficiency. Good agreement between simulated and measured results is observed in all cases. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:587-593, 2016 [ABSTRACT FROM AUTHOR]

The extraction behavior of the Rf homologs, Zr and Hf, has been studied in HCl, HNO, and HSO media using TEVA (a trioctyl and tridecyl methyl ammonium-based resin) and UTEVA (a diamyl amylphosphonate-based resin). All six systems were considered for the future chemical characterization of Rf. Batch uptake studies were first performed to determine which systems could separate Zr and Hf and these results were used to determine what acid concentration range to focus on for the column studies. The batch uptake studies showed that UTEVA separates Zr and Hf in all media, while the intergroup separation was only observed in HCl media with TEVA. Both HCl systems showed viability for potential extraction chromatographic studies of Rf. [ABSTRACT FROM AUTHOR]

A chemical separation system was developed to separate group 4 and 5 elements using extraction from HCl/HF solution into methyl-isobutyl-ketone (MIBK). The system is proposed to be applied for a confident assignment of the spontaneous fissioning radionuclide produced as decay product of element 115 either as dubnium (Db, Z = 105) or rutherfordium (Rf, Z = 104). Moreover, extraction systems are proposed allowing the investigation of chemical properties of Db in comparison to the properties of its lighter homologs Nb and Ta. [ABSTRACT FROM AUTHOR]

Recent studies of the chemical separation and characterization experiments of the first three transactinide elements, rutherfordium (Rf), dubnium (Db), and seaborgium (Sg), conducted atom-at-a-time in liquid phases, are reviewed. A short description on experimental techniques based on partition methods, specifically automated rapid chemical separation systems, is also given. A newly developed experimental approach to investigate single atoms of the heaviest elements with an electrochemical method is introduced. Perspectives for liquid-phase chemistry experiments on heavier elements are briefly discussed. [ABSTRACT FROM AUTHOR]

Solid-liquid extraction of the group 4 elements Zr and Hf, which are homologues of Rf ( Z = 104), and Th, a pseudo homologue, by triisooctylamine (TIOA) from HCl solutions was performed by batch method. After examining the time required to reach extraction equilibrium for these elements in various concentrations of TIOA and HCl, we investigated in detail variations in the distribution coefficients ( Kd) with TIOA and HCl concentrations. The Kd values of Zr and Hf increased with increasing the HCl and TIOA concentrations, suggesting an increase in the abundance of the anionic chloride complexes of Zr and Hf. On the other hand, the Kd values of Th were low in all the HCl concentrations studied, implying that Th does not form anionic species dominantly. We developed a new automated batch-type solid-liquid extraction apparatus for repetitive experiments on transactinide elements. Using this apparatus, we performed solid-liquid extraction employing the radioactive nuclides 89mZr and 175Hf produced by nuclear reactions and transported continuously from the nuclear reaction chamber by the He/KCl gas-jet system. It was found that the distribution behaviors in 7-11 M HCl are almost constant in the time range 10-120 s, and the Kd values are consistent with those obtained in the above manual experiment. This result suggests that the chemical reactions in the extraction process reach equilibrium within 10 s for Zr and Hf under the present experimental conditions. It took about 35 s for the extraction using the apparatus. These results indicate the applicability of the present extraction using the developed apparatus to 261Rf ( T1/2 = 68 s) experiments. [ABSTRACT FROM AUTHOR]

A novel temperature jump (T-jump) probe operational at B 0 fields of 600 MHz (14.1 Tesla) with an integrated cage radio-frequency (rf) coil for rapid (<1 s) heating in high-resolution (HR) liquid-state NMR-spectroscopy is presented and its performance investigated. The probe consists of an inner 2.5 mm “heating coil” designed for generating rf-electric fields of 190–220 MHz across a lossy dielectric sample and an outer two coil assembly for 1 H-, 2 H- and 15 N-nuclei. High B 0 field homogeneities (0.7 Hz at 600 MHz) are combined with high heating rates (20–25 K/s) and only small temperature gradients (<±1.5 K, 3 s after 20 K T-jump). The heating coil is under control of a high power rf-amplifier within the NMR console and can therefore easily be accessed by the pulse programmer. Furthermore, implementation of a real-time setup including synchronization of the NMR spectrometer’s air flow heater with the rf-heater used to maintain the temperature of the sample is described. Finally, the applicability of the real-time T-jump setup for the investigation of biomolecular kinetic processes in the second-to-minute timescale is demonstrated for samples of a model 14mer DNA hairpin and a 15 N-selectively labeled 40nt hsp17-RNA thermometer. [ABSTRACT FROM AUTHOR]

Band structure of the Z = 104 nucleus Rf has been a recent research focus in nuclear physics. We performed projected shell model calculations for this and some other neighboring Rf isotopes. Specifically, we studied rotational properties of these nuclei and showed that variations in dynamic moment of inertia were sensitive to single-particle structures, which may be useful information for locating the anticipated island of stability. Electromagnetic transition properties were also calculated, and measurable quantities were predicted for further experimental test. [ABSTRACT FROM AUTHOR]

Highlights: [•] Experimental verification of heat transfer through SC cables characterized by different electrical insulation wrapping schemes. [•] We measured the heat flux in the direction perpendicular to the side of the SC cable on which a compression force was applied. [•] These tests were performed in a pressurized superfluid helium environment. [•] We investigated the effect of pre-stress at room temperature to pressure applied on the samples at low temperature. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) shielding has become a phenomenon of great concern and there is growing demand towards the synthesis of materials with better EMI shielding effectiveness (EMI SE). This work highlights the preparation of Polyaniline-Yttrium Oxide (PANI-YO) composites for EMI shielding applications in the frequency range from 12.4 to 18 GHz (Ku-band). The structure and morphology of the composites were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). EMI SE, microwave absorption and reflection, dielectric properties of the composites are discussed in detail. All the computations were based on microwave scattering parameters measured by transmission line waveguide technique. The observed results show absorption dominant EMI shielding in these composites with EMI SE of −19 to −20 dB, which mainly depends on the dielectric loss of the composites. Through the results of our observations, we propose these composites to be potential materials for microwave absorption and EMI shielding applications. [ABSTRACT FROM AUTHOR]

Chemical studies of the heaviest elements in liquid phases at Japan atomic energy agency (JAEA) are reviewed. From the systematic investigation of ion-exchange chromatographic behavior of element 104, rutherfordium (Rf), based on an atom-at-a-time scale, it has been found that the properties of Rf are quite similar to those of the group-4 homologs, Zr and Hf, in the formation of chloride, nitrate, and sulfate complexes, although there are some differences in complexation strength between Rf and the lighter homologues. On the contrary, fluoride complex formation of Rf is significantly different from that of the homologues. Anionic fluoride complexation of element 105, dubnium (Db), has also been studied. The result clearly demonstrates that the fluoride complex formation of Db is considerably different from that of the group-5 homologue Ta, while the behavior of Db is similar to that of the lighter homologue Nb. A new electrochemical approach to the heaviest elements has been successfully conducted by a flow electrolytic column chromatographic method; the oxidation state of element 102, nobelium (No), with single atoms can be controlled with the developed apparatus. Prospects for the future studies on chemical properties of the heaviest elements at JAEA will be briefly considered. [ABSTRACT FROM AUTHOR]

The superheavy nucleus Rf, where rotational band and multi-quasiparticle isomer have been observed recently, has been investigated using total Routhian surface calculations and configuration-constrained calculations of potential energy surface, with the inclusion of β deformation. The experimental moment of inertial is well reproduced, indicating that the alignment is delayed due to the β deformation. A K = 5 or 8 state could form a two-quasiparticle isomer that is calculated to have higher fission barrier than the ground state. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the solubility of Zirconium dioxide ZrO2(c), a white crystalline oxide of zirconium, in water and aqueous perchloric acid solutions at 150 and 250°C. The study further examines the thermodynamic properties of the superheavy element rutherfordium (Rf) and its compounds. The study concluded that the solubility is pH independent in near neutral and slightly acidic solutions.

The 257Rf isotope has beéri populated via the 208Pb(50)Ti, n) fusion-evaporation reaction and delayed y-ray and electron decay spectroscopy has been performed. The existence of a high- K isomeric state in 257Rf has been confirmed. The isomeric state decays into a rotational band based on the 11/2-[725] excitation, which was observed up to spin of (23/2-). Three multipolarity-El y transitions depopulating the isomeric state have been observed, which fixes the spin for that state to (21/2+). This assignment agrees with theoretical predictions calculated with the microscopic-macroscopic approach, which suggest the isomeric state to be formed by coupling an unpaired 11/2- [725] quasineuiron to the (1/2-[521] ⊗ 9/2+[624])5- two-quasiproton state. The same two-quasiproton excitation is possible for the lowest isomer in 256Rf. [ABSTRACT FROM AUTHOR]

Production cross sections of Rf isotopes in the 248Cm + 180 reaction were measured at the beam energy range of 88.2 to 101.3 MeV by use of a gas-filled recoil ion separator. The excitation functions of 260Rf,261Rfa, and262Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to 261Rfb and a longer-lived state of 262Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the 18O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of 261Rf, whereas it was quite different from those of 260Rf and 262Rf. A few-second spontaneously fissioning nuclide previously reported as 261Rfb and 261Rf observed in 248Cm + 18O reaction was identified as 261Rfb. [ABSTRACT FROM AUTHOR]

The ground state band was recently observed in the superheavy nucleus 256Rf. We study the rotational properties of 256Rf and its neighboring even-even nuclei by using a cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method in which the blocking effects are taken into account exacüy. The kinematic and dynamic moments of inertia of the ground state bands in these nuclei are well reproduced by the theory. The spin of the lowest observed state in 256Rf is determined by comparing the experimental kinematic moments of inertia with the PNC-CSM calculations and agrees with previous spin assignment. The effects of the high order deformation s6 on the angular momentum alignments and dynamic moments of inertia in these nuclei are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Thin films of polymerized acetylene have been deposited by Plasma Enhanced Chemical Vapor Deposition with a capacitively coupled RF discharge of acetylene. From the results of elemental analysis, FTIR, 1H-NMR and electrical conductivity, a highly branched chemical structure for the polymeric film is proposed. The morphology of the film surface, as well as its thickness was determined by scanning electron microscopy. The optical constants of the film, refractive index and optical band gap energy were obtained by the UV–vis transmittance spectrum using different models from the literature. The films presented a moderate degree of hydrophobicity and showed a high capacity to absorb and retain benzene after drying at room temperature during 24h. This result shows the potential of the obtained polymer to be used in filler of filters employed for the treatment of industrial effluents. [Copyright &y& Elsevier]

Background: The symmetry-guided methods have shown their power over many years of nuclear physics research. It was found that the concept of the pseudospin symmetry is very helpful in providing a simple explanation of many features of heavy nuclei. Purpose: To show, based on the results of calculations of the energies of the γ-vibrational states in nuclei with Z ~ 100, that the experimental data on these energies will give us information indicating how well the pseudospin symmetry is realized in these exotic nuclei. Method: The quasiparticle-phonon model is used to calculate the energies of the γ-vibrational states. Results: It is shown that the energies of the γ--vibrational states in the Cm, Cf, Fm, No, and Rf isotopes considered as the functions of the number of neutrons N have a minimum at N = 156 when the neutron Fermi level lies just between the following neutron single particle levels: 3/2[622] and 1 /2[620] which belong to the pseudospin doublet. It is shown that the corresponding two-quasiparticle component gives the main contribution to the structure of the γ- phonon. Conclusion: The experimental information on the energies of the γ-vibrational states in nuclei with Z ~ 100 can be used to determine a splitting of the [521] pseudospin doublet. [ABSTRACT FROM AUTHOR]

Abstract: Chromium dioxide (CrO2) thin film has generated considerable interest in applied research due to the wide variety of its technological applications. It has been extensively investigated in recent years, attracting the attention of researchers working on spintronic heterostructures and in the magnetic recording industry. However, its synthesis is usually a difficult task due to its metastable nature and various synthesis techniques are being investigated. In this work a polycrystalline thin film of CrO2 was prepared by electron beam vaporization of Cr2O3 onto a Si substrate. The polycrystalline structure was confirmed through XRD analysis. The stoichiometry and elemental depth distribution of the deposited film were measured by ion beam nuclear analytical techniques heavy ion elastic recoil detection analysis (ERDA) and Rutherford backscattering spectrometry (RBS), which both have relative advantage over non-nuclear spectrometries in that they can readily provide quantitative information about the concentration and distribution of different atomic species in a layer. Moreover, the analysis carried out highlights the importance of complementary usage of the two techniques to obtain a more complete description of elemental content and depth distribution in thin films. [Copyright &y& Elsevier]

Abstract: The structural and electronic properties of rutherfordium, the latest group IV B element, have been evaluated by first principles density functional theory in scalar relativistic formalism with and without spin–orbit coupling and compared with its 5d homologue Hf. It is found that Rf will crystallize in the hexagonal close packed structure as in Hf. However, under pressure, it will have different sequence of phase transitions than Hf: instead of . An explanation is offered for this difference in terms of the competition between the band structure and the Ewald energy contributions. [Copyright &y& Elsevier]

A novel single feed aperture-coupled wideband dielectric resonator antenna (DRA) exhibiting righ-handed circular polarization (RHCP) operating in the Ku-band frequency range is presented. The aperture-coupled single feed design utilizes back-side microstrip excitation through a novel bow-tie-shaped cross-slots in the ground plane. Extensive simulation parametric studies resulted in a 3 dB axial ratio (AR) bandwidth of 17.24% at a center frequency of 13 GHz, where the dielectric resonator is excited in its HEM11δ resonant mode. A prototype DRA was fabricated with some limitations and experimentally verified for the impedance matching and radiation patterns showing circular polarization. [ABSTRACT FROM AUTHOR]

Relativistic basis sets of double-zeta, triple-zeta, and quadruple-zeta quality have been optimized for the 6d elements Rf-Cn. The basis sets include SCF exponents for the occupied spinors and for the 7p shell; exponents of correlating functions for the valence shell, the 6s and 6p shells, and the 5f shell; and exponents of functions for dipole polarization of the 6d shell. A finite nuclear size was used in all optimizations. Prescriptions are given for constructing contracted basis sets. The use of the basis sets is demonstrated for some atomic and molecular systems. The basis sets are available as an Internet archive and from the Dirac program Web site, . [ABSTRACT FROM AUTHOR]

Niobium oxide films have been grown by reactive rf sputtering in a vacuum system and characterized by absorption spectroscopy and X-ray diffraction. The thickness of the (optically transparent) films has been determined as a function of sputtering time by examining interference effects in a plane-parallel layer. The average deposition rate is determined to be 7.4 ± 0.3 Å/min (95% confidence interval). [ABSTRACT FROM AUTHOR]