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Jensen (Can. J. Phys. 98, 506 (2020). doi:10.1139/cjp-2019-0395) presents theoretical justification for the claim that linear triatomic molecules are necessarily observed to be bent. The basis of the assertion is that the expectation value of the supplement of the bending angle, [bar.[rho]] used in Jensen's paper, is calculated to be positive. In this comment, we examine the interpretation of the expectation values of [bar.[rho]] in stationary states, and indicate that Jensen's claim contradicts a basic principle of quantum mechanics that the energy and geometrical variables cannot have definite values at the same time. Key words: linear molecule, bending angle, expectation value, permanent dipole moment, vibration rotation spectra. Jensen (Can. J. Phys. 98, 506 (2020). doi:10.1139/cjp-2019-0395) presente une justification theorique a l'affirmation que les molecules triatomiques sont necessairement observees etre courbees. La base de cette assertion est que la valeur attendue du supplement d'angle de courbure, [bar.[rho]], definie par Jensen est calculee etre positive. Dans le present commentaire, nous examinons l'interpretation de [bar.[rho]] dans des etats stationnaires et montrons que leur affirmation contredit un principe de base de la mecanique quantique, qui dit que l'energie et les variables geometriques ne peuvent avoir des valeurs definies simultanement. Mots-cles : molecule lineaire, angle de courbure, valeur attendee, moment dipolaire permanent, spectres de vibration rotation., 1. Introduction In the paper [1], Jensen claims that linear triatomic molecules are necessarily observed as being bent on ro-vibrational average [2-5]. More recently Jensen and coworkers published a paper [...]

We have reported energies and electric dipole transition parameters, such as transition probabilities, oscillator strengths, line strengths, and wavelengths for Na-like gold ([Au.sup.68+], Z = 79) using AUTOSTRUCTURE atomic code. Calculations include Breit and QED contributions besides correlation effects. A few of the results have been compared with available theoretical and experimental results in the literature. Our atomic structure data for sodium-like gold are in good agreement with others. Also we have presented new results for electric dipole transitions in sodium-like gold. Key words: energies, correlation effects, Breit and QED contributions, electric dipole transitions. Nous rapportons les energies et des parametres de transition dipolaire electrique, comme les probabilites de transition, les forces d'oscillateur, les intensites de raie et les longueurs d'onde pour de l'or de type Na ([Au.sup.68+], Z = 79) en utilisant le programme atomique AUTOSTRUCTURE. Les calculs incluent les contributions de Breit et QCD/EDQ en plus des effets de correlation. Quelques-uns de nos resultats sont compares avec les donnees theoriques et experimentales dans la litterature. Nos resultats sont en bon accord avec les autres. Nous presentons des resultats inedits sur les transitions dipolaires electriques dans l'or de type Na. [Traduit par la Redaction] Mots-cles: energies, effets de correlation, contributions de Breit et de QED/EDQ, transitions dipolaires electriques., 1. Introduction Gold has been a significant element that plays important roles in magnetic fusion and high energy density plasmas [1]. Accurate atomic structure and spectral data of highly ionized [...]

The quantum mechanical problem of a hydrogen atom placed at the center of an impenetrable sphere of radius [r.sub.0] is solved by using two different methods, where, in the first, a trial wave function, consisting of a hydrogen-like function times a cutoff factor that ensures fulfillment of Dirichlet boundary condition, is proposed, whereas in the second, the radial Schrodinger equation is solved by means of an accurate numerical technique. We computed the energies for the ground and first excited states of S-, P-, and D-symmetry, as well as dipole transitions, oscillator strengths, and a few state lifetimes. Although the variational method and the numerical solution are found to give similar qualitative behaviours, which, in general, compare reasonably well with some results published previously, the 2p state lifetimes obtained in the present calculations appear to be at variance with the latter at some particular box radii. Key words: confined hydrogen atom, variational calculations, dipole transitions, oscillator strengths, lifetime. Deux methodes sont ici utilisees pour etudier le probleme quantique d'un atome d'hydrogene place au centre d'une sphere impenetrable de rayon [r.sub.0]. Dans la premiere, nous proposons une fonction d'onde d'essai qui consiste en une fonction de type hydrogene, avec un seuil de coupure de facon a satisfaire la condition limite de Dirichlet. Dans la seconde, nous solutionnons l'equation radiale de Schrodinger par methode numerique precise. Nous calculons les energies pour le fondamental et les premiers etats excites de symetrie S, P et D, ainsi que les transitions dipolaires, les forces d'oscillateur et les temps de vie pour quelques etats. Meme si la methode variationnelle et la solution numerique decrivent qualitativement le meme comportement en general, et se comparent raisonnablement bien avec des resultats deja publies, le temps de vie de l'etat 2p obtenu ici est en desaccord avec ces derniers pour certains rayons. [Traduit par la Redaction] Mots-cles: atome d'hydrogene confine, calcul variationnel, transitions dipolaires, forces d'oscillateur, temps de vie., 1. Introduction Confined quantum systems have prompted a wide variety of applications in physics and chemistry, where some refer to the electronic structure of atoms and molecules subjected to external [...]

Ab initio investigation has been performed for the strontium hydride cation Sr[H.sup.+] using a standard quantum chemistry approach. It is based on the pseudopotentials for atomic core representations, Gaussian basis sets, as well as with full configuration interaction calculations. A diabatisation procedure based on the effective hamiltonian theory and an effective metric is used to produce the quasi-diabatic potential energy. Adiabatic and quasi-diabatic potential energy curves and their spectroscopic parameters for the ground and many excited electronic states of [sup.1,3][Σ.sup.+], [sup.1,3]Π, and [sup.1,3]Δ symmetries have been determined. Their predicted accuracy is discussed by comparing our well depths and equilibrium positions with the available experimental and theoretical results. Moreover, we localized and analyzed numerous avoided crossings between the electronic states of 1³[Σ.sup.+] and 1-3n symmetries. The correction of the electron affinity of the H atom is also considered, for the 1-10¹[Σ.sup.+] electronic states, to improve the accuracy of the adiabatic potential energies of these states. In addition, we calculated the dipole moments, for a wide range of internuclear distances in both diabatic and quasi-diabatic representations. The adiabatic permanent dipole moments for the 10¹[Σ.sup.+] electronic states revealed ionic characters related to electron transfer and yields both Sr[H.sup.(+)] and [Sr.sup.(+)]H arrangements. The transition dipole moments between neighbor electronic states revealed many peaks around the avoided crossing positions. Key words: pseudopotentials, configuration interaction, potential energy curves, spectroscopic parameters, dipole moments. Nous avons complete une etude ab initio du cation hydride du strontium Sr[H.sup.+] en utilisant une approche de chimie quantique standard. Elle est basee sur les pseudo-potentiels pour representer le creur atomique, sur des ensembles de base gaussiens et des calculs avec interaction a pleine configuration. Nous utilisons une procedure de diabatisation basee sur la theorie du Hamiltonien effectif et une metrique effective est utilisee pour produire l'energie potentielle quasi-diabatique. Nous determinons les courbes d'energie potentielle adiabatique et quasi-diabatique pour le fondamental et plusieurs etats excites des symetries [sup.1,3][Σ.sup.+], [sup.1,3]Π et [sup.1,3]Δ. La precision de nos predictions est analysee en comparant nos profondeurs de puits et nos positions d'equilibre avec les valeurs theoriques et experimentales disponibles. De plus, nous localisons et analysons les nombreux croisements evites entre les etats electroniques des symetries 1³[Σ.sup.+] et [sup.1,3]Π. Nous considerons aussi la correction de l'affinite electronique de l'atome H pour les etats 1-10¹[Σ.sup.+], de facon a ameliorer la precision des energies potentielles adiabatiques de ces etats. Les moments dipolaires sont calcules pour un large domaine des distances internucleaires, dans les deux representations, diabatique et quasi-diabatique. Les moments dipolaires adiabatiques permanents pour les etats electroniques 10¹[Σ.sup.+] revelent des caracteres ioniques relies au transfert d'electron et donnent les deux arrangements Sr[H.sup.(+)] et [Sr.sup.(+)]H. Les moments dipolaires de transition entre etats electroniques voisins revelent plusieurs pics autour des positions des croisements evites. [Traduit par la Redaction] Mots-cles: pseudo-potentiel, interaction de configuration, courbes d'energie potentielle, parametres spectroscopiques, moments dipolaires., 1. Introduction In the recent past, there has been considerable interest in the creation of ultracold molecules at temperatures below 1 µK by magneto-association [1, 2] or photo-association [3, 4], [...]

The standard model of particle physics accurately describes all particle physics measurements made so far in the laboratory. However, it is unable to answer many questions that arise from cosmological observations, such as the nature of dark matter and why matter dominates over antimatter throughout the Universe. Theories that contain particles and interactions beyond the standard model, such as models that incorporate supersymmetry, may explain these phenomena. Such particles appear in the vacuum and interact with common particles to modify their properties. For example, the existence of very massive particles whose interactions violate time-reversal symmetry, which could explain the cosmological matter-antimatter asymmetry, can give rise to an electric dipole moment along the spin axis of the electron. No electric dipole moments of fundamental particles have been observed. However, dipole moments only slightly smaller than the current experimental bounds have been predicted to arise from particles more massive than any known to exist. Here we present an improved experimental limit on the electric dipole moment of the electron, obtained by measuring the electron spin precession in a superposition of quantum states of electrons subjected to a huge intramolecular electric field. The sensitivity of our measurement is more than one order of magnitude better than any previous measurement. This result implies that a broad class of conjectured particles, if they exist and time-reversal symmetry is maximally violated, have masses that greatly exceed what can be measured directly at the Large Hadron Collider.An experimental measurement of the electric dipole moment of the electron with sensitivity an order of magnitude better than previous studies increases the accessible mass range of fundamental particles by a factor of three., Author(s): [sup.1] Author Affiliations:(1) Department of Physics, Harvard University, Cambridge, USA(2) Department of Physics, Yale University, New Haven, USA(3) Center for Fundamental Physics, Northwestern University, Evanston, USA(4) Division of Physics, [...]

The absorption and emission spectra of fluorescent thiophene dye, namely, 2,5- di-(5-tert-butyl-2-benzoxazolyl) thiophene, have been recorded at room temperature in solvents of different polarities. The excited state dipole moments ([μ.sub.e]) were estimated from Lippert's, Bakhshiev's, and Kawski-Chamma-Viallet's equations using the variation of Stoke's shift with the solvent dielectric constant and refractive index. The optimized geometry of the molecule and [μ.sub.g] were calculated theoretically by Gaussian 03 software using B3LYP/6-31[g.sup.*] level of theory. The [μ.sub.g] and [μ.sub.e] were calculated by means of solvatochromic shift method and [μ.sub.e] was determined in combination with [μ.sub.g]. It was observed that [μ.sub.e] were higher than those of the [μ.sub.g], indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected thiophene dye. Further, the change in the dipole moment (Δμ) was calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter ([E.sup.N.sub.T]}) and values are compared. PACS Nos.: 33.50.-j, 87.64.i, 31.70.Hq, 87.15.kg. Nous avons enregistre, a la temperature de la piece et dans des solvants de differentes polarites, les spectres d'absorption et d'emission du colorant thiophene fluorescent 2,5-di-(5- tertbutyl-benzoxazolyl). Nous estimons le moment dipolaire ([μ.sub.e]) des etats excites a partir des equations de Bakhshiev et Kawski- Chamma-Viallet en utilisant la variation du deplacement de Stokes, avec la constante dielectrique du solvant et l'indice de refraction. La geometrie de la molecule est completement optimisee et nous calculons [μ.sub.g] a l'aide du logiciel Gaussian 03 utilisant le modele theorique B3LYP/6-31[g.sup.*]. Les parametres [μ.sub.e] et [μ.sub.e] sont calcules par la methode du deplacement solvatochromique et [μ.sub.e] est determine en combinaison avec [μ.sub.g]. Nous observons que les valeurs de ixe sont plus elevees que celles de [μ.sub.g], ce qui indique une redistribution substantielle des densites d'electrons π dans un etat excite plus polaire pour le colorant thiophene choisi. De plus, nous evaluons les changements du moment dipolaire (Δμ) a partir de deux methodes, celle du deplacement solvatochromique et sur la base d'un parametre de polarite empirique microscopique ([E.sup.N.sub.T]) et nous comparons ensuite les resultats. [Traduit par la Redaction], 1. Introduction The effect of solvents on the absorption and fluorescence characteristics of organic compounds has been a subject of interesting investigation [1-5]. Excitation of a molecule by photon causes [...]

The response to electrostatic fields by finite systems, which contain a large central region of chemically identical building blocks, is shown not to depend on the boundaries of the system. Consequently, we can determine this response from that of the corresponding infinite periodic system and a vector potential theoretical-computational approach is presented for doing so. Both the electronic and structural response can be obtained with our approach. In many cases, neglecting the structural response is a poor approximation. To illustrate the performance of our treatment, extensive calculations have been carried out for simple model systems. Selected results are reported. Key words: polarization, extended systems, electrostatic fields, structural properties, electronic properties. On demontre que, pour des systemes finis contenant une grande region de blocs chimiquement identiques, la reponse a des champs electrostatiques ne depend pas des limites du systeme. En consequence, on peut determiner cette reponse a partir des systemes infinis correspondants et on presente une approche par calculs theoriques des potentiels vectoriels qui permet d'y arriver. Avec notre approche, il est possible d'obtenir aussi bien la reponse electronique que structurelle. Dans plusieurs cas, si on neglige la reponse structurelle, on obtient une mauvaise approximation. Afin d'illustrer la performance de notre traitement, on a effectue des calculs extensifs de systemes modeles simples. On rapporte des resultats choisis. Mots-cles : polarisation, systemes etendus, champs electrostatiques, proprietes structurelles, proprietes electroniques., [Traduit par la Redaction] Introduction With this contribution, we want to honor Tom Ziegler on the occasion of his 65th birthday. It happens that Tom Ziegler shares a number of [...]

The Wien effect, that is, the dependence of the electrical conductivity of dilute suspensions of soil particles on electrical field strength, was explored in the intermediate field-strengths range of 0.9 x [10.sup.6] to 5 x [10.sup.6] V [m.sup.-l], at higher resolution than in previous studies. This enabled the detection of a local minimum in the electrical conductivity-field strength relationship in which the declining phase is termed the negative Wien effect. Suspensions of clay-size soil particles of three soil types, with various mono-, di-, and trivalent cations, were tested. A negative Wien effect was observed with homoionic soil particles saturated with divalent cations, with electrodialyzed soil particles, and with suspensions of black soil particles that contained organic matter. Two quantifiers of the declining and increasing slopes: (i) polarizability (counter ion polarization and re-adsorption); (ii) ion-stripping intensity--on the respective sides of the local minimum were used for characterizing the interaction between the soil particles and the counter ions. The higher mean ion-stripping intensities found for the [Na.sup.+] suspensions--twice those for the [K.sup.+] suspensions--reflect the easier stripping off of the Na cations and the stronger adsorption of the K cations. The mean ion-stripping intensities of all divalent cations for the three soils were lower than those determined for the monovalent ones, which reflects the tighter binding of the divalent cations. The [Ca.sup.2+] and [Zn.sup.2+] ions were stripped off most easily from the surfaces of soil particles, and tighter binding was found for [Pb.sup.2+] to brown soil and black soil, and for [Cd.sup.2+] to yellow-brown soil. In general, lower polarizabilities were correlated with higher ion-stripping intensities (e.g., for [Ca.sup.2+] and [Zn.sup.2+]). However, the exceptions (e.g., the polarizabilities of [Cu.sup.2+] and [Pb.sup.2+] shed more light on the interaction between the soil particles and the cations. The proposed method of characterization is superior to other methods for characterizing soil particle-counter ion interactions because it characterizes adsorption directly and not via exchange measurement, and it is less laborious than, for example, exchange isotherm measurements. Abbreviations: DL, double layer; EC, electrical conductivity; i.d.m., induced dipole moment; OM, organic matter.

We report on interferometric characterization of a deep parabolic mirror with a depth of more than five times its focal length. The interferometer is of Fizeau type; its core consists of the mirror itself, a spherical null element, and a reference flat. Because of the extreme solid angle produced by the paraboloid, the alignment of the setup appears to be very critical and needs auxiliary systems for control. Aberrations caused by misalignments are removed via fitting of suitable functionals provided by means of ray tracing simulations. It turns out that the usual misalignment approximations fail under these extreme conditions. OCIS codes: 260.0260, 120.0120, 120.3180, 220.4840.

A theoretical study was done of the electronic structure of the molecular ion [NaCs.sup.+]. The calculation is based on nonempirical pseudopotentials and parameterized l-dependent polarization potential. Gaussian basis sets were used for both atoms and spin-orbit effects were taken into account. Potential energy curves were obtained for 56 lowest electronic states for the symmetries ²[Σ.sup.+], ²Π, ²Δ, and Ω of the molecular ion [NaCs.sup.+]. The spectroscopic constants were calculated for 19 electronic states by fitting the calculated energy values to polynomials in terms of the internuclear distance r. Through the canonical functions approach the eigenvalue [E.sub.v], the rotational constant [B.sub.v] and the abscissas of the turning points were calculated up to 52 vibrational levels for 6 bound states. The dipole moment were calculated in the considered range of the internuclear distance r. The comparison of the calculated values to those available in the literature shows a good agreement. PACS Nos.: 31.10.+z, 31.15.Ar, 31.50.Df, 33.15.Mt Nous avons complete une etude theorique de la structure electronique de l'ion moleculaire [NaCs.sup.+]. Le calcul est base sur des pseudopotentiels non empiriques et sur un potentiel de polarisation dependant de l. Nous avons utilise une base gaussienne pour les deux atomes et nous avons tenu compte des effets de spin-orbite. Nous obtenons les courbes equipotentielles pour les 56 etats de plus basse energie dans les symetries ²[Σ.sup.+], ²Π, ²Δ et Ω de l'ion moleculaire [NaCs.sup.+]. Nous avons calcule les constantes spectroscopiques pour 19 etats electroniques par ajustement polynomial des energies calculees en fonction de la separation internucleaire r. Via une approche en fonctions canoniques, nous avons evalue la valeur propre [E.sub.v], la constante rotationnelle [B.sub.v] et l'abcisse du point tournant jusqu'a 52 etats vibrationnels pour 6 etats lies. Nous avons calcule le moment dipolaire dans le domaine considere de la distance internucleaire r. La comparaison des valeurs calculees avec les valeurs experimentales publiees montre un bon accord. [Traduit par la Redaction], 1. Introduction Collisions between alkali-metal ions have been studied since the early work of Perel et al. [1, 2], Daley and Perel [3],Aquilanti et al. [4-10], Brunetti et al. [11], [...]

I derive the effective phase of the spin precession for a neutral particle with spin 1/2 moving in a superposition of constant and radio frequency fields. The fields are perpendicular to each other at all times, and the radio frequency field is slowly rotating with angular speed [omega]. The derivation is accomplished with the help of the exact solution of the Schr6dinger equation. I show that the geometrical (or Berry) phase is the linear term in the power series expansion of the effective phase in terms of [omega]. I also discuss the role of the Berry phase in the experimental search for an electric dipole moment of the neutron with ultracold neutrons. [DOI: 10.1119/1.2805237]

A model quaternary system consisting of three deuterated solutes are studied. Three different numerical approaches are used to determine the individual limiting solute molar polarizations from the multicomponent solutions.

The induced-dipole-electric-field contribution to the refractive index at any location within a nanometer-scale dielectric is quantified by summing the electronic dipole contributions due to all the surrounding atoms in the dielectric. Using a tetragonal lattice and varying the ratio of lattice constants illustrates the important limiting chainlike and planelike behaviors. Strong polarizing effects and thus high refractive indices occur for an electric field applied along the length of a chain of atoms or applied in a planar direction to a plane of atoms. In contrast, a strong depolarizing effect and thus low refractive indices occur for an electric field applied normal to a chain of atoms or applied normal to a plane of atoms. Birefringence is increased or decreased by the simultaneous presence or absence of polarizing and depolarizing effects. OCIS codes: 160.4760, 160.1190, 160.3130.

Abstract: We dicuss the utility of precision probes for flavour-diagonal CP-violation, namely, searches for electric dipole moments of nucleons, atoms, and molecules, in looking for new physics thresholds that manifest [...]

A complete scattering matrix representation for the ideal equal-delay topology for transformers and hybrid networks is presented. It is shown that while the operation of the hybrid as a 180[degrees] power combiner, current balun, or voltage balun is essentially frequency independent, the operation as a 0[degrees] power combiner or splitter is not. Instead, the isolation between the 0[degrees] and 180[degrees] ports is finite and frequency dependent. Moreover, the reflection coefficient at the sum port is nonzero and frequency dependent. These characteristics lead to the conclusion that while the equal-delay 180[degrees] power splitter/combiner is fundamentally frequency independent, its 0[degrees] counterpart is limited to operation well below the fundamental quarter-wave frequency of the constituent transmission lines. Full three-port scattering parameter representations, which are compatible with the calibration and analysis approach given in the CISPR 16-1 specification, are given for the three fundamental transformer and balun types derivable from the equal-delay hybrid: 1 the Guanella voltage balun, 2 the Guanella current balun, and 3 the 180[degrees] power divider or terminated hybrid balun, as specified in the CISPR 16-1 specification. Index Terms--Balancing network, balun, calculable dipole, CALTS, CISPR 16-1, equal-delay balun, equal-delay transformer, Guanella balun, Guaneila transformer, site attenuation, ultra wideband, UWB.

We present a simple experiment to measure the magnetic dipole moment of a magnet using two identical magnets and spring dynamometers. The experiment illustrates the concept of a dipole field, as well as the interaction between two magnetic dipoles. The validity of the magnetic dipole approximation is discussed. The experiment also makes it possible to obtain the remanent magnetization of rare earth magnets. [DOI: 10.1119/1.2180286]

Quadrupolar charge fields of molecules and of molecular fragments give rise to unique features in weakly interacting clusters and aggregations. Relative to dipole-dipole interactions, the interactions among quadrupolar molecules tend to allow for greater orientational distortions away from equilibrium.

Residual dipolar couplings offer a view of dynamic processes that is very complementary to other NMR spectroscopic approaches. A number of different residual dipolar coupling-based approaches are discussed to the characterization of molecular dynamics, all of which have their own specific limitations.

Electron capture dissociation was implemented in a digital ion trap without using any magnetic field to focus the electrons. Since rectangular waveforms are employed in the DIT for both trapping and dipole excitation, electrons can be injected into the trap when the electric field is constant. Following deceleration, electrons reach the precursor ion cloud. The fragment ions produced by interactions with the electron beam are subsequently analyzed by resonant ejection. [[Glu.sup.1]]-Fibrinopeptide B and substance P were used to evaluate the performance of the current design. Fragmentation efficiency of 5.5% was observed for substance P peptide ions. Additionally analysis of the monophosphorylated peptide FQ[pS]EEQQQTEDELQDK shows that in the resulting c- and z-type ions, the phosphate group is retained on the phophoserine residue, providing information on which amino acid residue the modification is located.

A rich variety of structures of putative global energy minima for clusters bound by the Stockmayer (Lennard-Jones plus point dipole) potential and these are revealed as the cluster size and dipole strength is varied. Closed-loop structures with the topology of knots and links are most remarkable groups.

A study to present specific hypothesis that satisfactorily explain the boiling point of a number of molecules, CH(sub w)F(sub x)Cl(sub y)Br(sub z) having similar structure, and then analyze the model with the help of multiple linear regression(MLR), a data analysis tool. The MLR analysis was useful in selecting the predictor variables that could significantly clarify the boiling point variation of CH(sub w)F(sub x)Cl(sub y)Br(sub z) molecules.

A way to control the TiO2 energy levels by adsorption of a series of organic molecules with different dipole moments, together with the dye molecules is reported. The results can be explained consistently in terms of a dipole-related shift of E( sub conduction band) with respect to E(sub redox).

The dipole-dipole interactions between a linear array of optically driven silver metallic nanospheres (MNSs) are described. The model calculations incorporate the full electric field generated by an oscillating dipole and predict several interesting effects due to the retardation of the field.

Ab initio calculations on model structures and an analysis of charge densities using the theory of atoms in molecules are presented. It is found that the maximum possible impact of local dipole-dipole interactions is insufficient to account for the observed reactivity differences.

Measurements of static microscopic dielectric response of several dipolar solvents to charge redistribution in a fluorescent probe are reported. A possible reason for the macroscopic-like behavior and a connection between the anomaly and fluctuating structures formed by anomalous solvents near the hydrophobic surface of the probe is discussed.

The study developed a simple potential model for polar molecules, which represents effectively and accurately the thermodynamics of dilute gases. The model is used to predict the critical temperature of Stockmayer fluids for variable dipole moment and is applied to HCL as an example of a real molecule.

CaC(sub n), CaC(sub n)(super +), and CaC(sub n)(super -) (n = 1-8) monocyclic clusters are studied by using the B3LYP density functional method. Predictions for several molecular properties that could help in possible experimental characterization, such as equilibrium geometries, electronic structures, dipole moments, and vibrational frequencies are reported.

A methodology for the determination of solution structures of small molecules from residual dipolar coupling constants measured in dilute liquid crystals is developed. The study shows that reducing the degree of order by using dilute liquid crystralline media in combination with precise measurement of small residual dipolar coupling constants, is a way of overcoming the limitation of strongly orienting liquid crystals associated with the complexity of 1H NMR spectra for molecules with more than 12 protons.

We report a theoretical study of the two lowest singlet electronic states ([X.sup.1] [A.sub.1] and [A.sup.1][B.sub.1]) of silylene Si[H.sub.2]. These states become degenerate as [a.sup.1] [[delta].sub.g] state at linear configurations and are subject to the Refiner effect. In ab initio calculations we have determined the potential energy and dipole moment surfaces for each state, and the transition moment surface between the states. Parameterized analytical functions have been fired through the various sets of ab initio points, and the parameter values obtained for the potential energy surfaces have been further refined in fittings to experimental spectroscopic data. In these latter fittings, we use as input data experimentally derived energy differences together with ab initio points. In this manner, we achieve refined potential energy surfaces that behave reasonably also in regions of configuration space that are not sampled by the wavefunctions of the states for which experimentally derived energies are available. The calculation of rovibronic energies, the fittings to experimentally derived energies, and simulations of [A.sup.1] [right arrow] [A.sup.1] emission spectra of Si[H.sub.2] have been carded out with the RENNER program system. The higher excited vibrational states of [X.sup.1][A.sub.1] Si[H.sub.2] form polyads of heavily interacting states and many polyad states have been observed in dispersed fluorescence studies. The present theoretical work shows that owing to the heavy interaction between the states in the polyads, it is difficult to obtain unambiguous assignments for them. Key words: silylene, RENNER, ab initio.

Dust-dust interactions in complex plasmas have been studied when effects of an external magnetic field become important. It is shown that the forces from particle magnetization may result in mutual repulsion as well as attraction. It was found that magnetized grains coalesce, forming field-aligned chains. Since the 'disruptive' electrostatic forces increase with the distance from the centre of a chain, whereas the 'cohesion' magnetic forces decrease, there is an intrinsic length scale for these particle chains. A model was developed to determine the length of these structures. These finding were then applied to recent complex plasma experiments with paramagnetic particles. Index Terms--Complex plasmas, dipole moment, dust-dust interactions, particle agglomeration.

We provide examples of how a computer algebra system can be used to investigate the motion of an electric charge in an electric or magnetic dipole field. [DOI: 10.1119/1.1579496]

Investigating two new options for hollow superconducting cables aimed at increasing structural current density were proposed and designed in the frameworks of R&D program for the future accelerator facility at GSI is presented. The data from cable short sample test are presented.

An experiment is described, conducted at Los Alamos National Laboratory, Los Alamos, NM, which aims to measure the neutron electric dipole moment (EDM) to 4 x 10[superscript -28].

A simple model of signals transmitted by global positioning system (GPS) satellites and of the reception of these signals by GPS receiver is presented. The model idealizes the receiver and transmitter as electric dipole antennas.

A 2-m electrostatic hexapole field was used in the direct determination of permanent dipole moments and structures of A1-Ch3Cn and A1-NH3.

The harmonic balance technique has been used to investigate the impact of permanent dipole moments of quantized states on intersubband harmonic generation based on quantum-interference induced transparency in semiconductor quantum wells. It is concluded that the permanent moments prompt a shift of the pump photon energy at which the conversion efficiency is greatest.

Chemistry research is presented describing the study of maltose binding protein to determine its dipolar couplings.

The Nb3Sn strands for Fermilab's high field dipole models were investigated and results of heat treatment optimization studies are reported.

The measurement of the dipole moment of aniline in its S1 state is presented.

The vibrational Stark effect (VSE) measurements for nitric oxide (NO) bound to a picket fence porphyrin and several distal pocket mutants of Mb, which were designed to perturb the electrostatic field near the heme as probed by iron redox potential shifts, pK(sub a) and spectral shifts, and IR band shifts, are reported. The dispersion seen in v(sub NO) and v(sub CO) are modeled as electrochromic band shifts and the variations are quantitatively described by the measured ratio delta mu(sub NO)/delta mu(sub CO) got from the VSE data.

Research into the treatment of dipole moments, polarizabilities and hyperpolarizabilities is presented.

Density functional theory schemes based on conventional exchange-correlation functionals have been used to establish dipole moment, polarizability, and first and second hyperpolarizabilities of push-pull pi-conjugated systems. It is concluded that current exchange-correlation functionals do not accurately describe the polarization of conjugated systems when the polarization is the result of donor/acceptor substitution or an external field or both.

Research is presented describing the use of single-crystal X-ray analysis to confirm the structure of a tetrazine ylide produced by the reaction of sodium azide and dichlorobenzaldazine.

The ground and excited-state dipole moments of free base chlorin and cis and trans free base isobacteriochlorin are presented. This research used dielectric constant measurements of H2Ch/benzene solutions.

Issues concerning the molecular dynamics of 1,4-dioxane and 1,3-dioxane are presented in an attempt to understand the polar solvent in solute-solvent interactions of 1,4-dioxane.

A new time-dependent quantum inversion algorithm is reported, operating independently of the dipole moment function in a system.

Research was conducted to characterize magnetic force microscopy (MFM) thin film tips as a function of an external magnetic field. Using current carrying rings with radii ranging from between 603 and 2369 nm fabricated by electron-beam lithography directly imaged by MFM, well defined magnetic stray fields were generated. Results provide a quantitative relationship on how absolute values of the magnetic dipole and monopole moments and their location within the tip depend on the magnetic dipole and monopole moments.

Research was conducted to examine in detail the vibrational assignment of liquid bromobenzene. To separate the integrated intensities due to various transitions, the imaginary molar polarizability spectrum was fitted between 3240 and 140 cm-1. The calculation of the transition moments and squares of the dipole moment derivatives with respect to normal coordinates for bromobenzene was carried out. Comparison with other experimental results for benzene-d was performed.