Moments Of Excited States Research Articles

Excited state dipole moments of two dicyanobenzene isomers from thermochromic shifts and ab initio calculations

The excited state dipole moments of two positional isomers of dicyanobenzene have been determined from thermochromic shifts of the absorption and fluorescence emission spectra in ethyl acetate solution and compared to the results of ab initio calculations. We found that the dipole moments of excited states from thermochromic shifts closely resemble the ab initio values of the isolated molecule, while the results of conductor-like screening model (COSMO) using the same wave function model as for the isolated molecule, shows considerable deviations from the experimental values. It is shown that the dipole moments of the two cyano groups add up vectorially for both the ground and excited states.

Evaluation of dipole moments of indole derivative (5-MPIC) by Solvatochromic shift method

The Solvatochromic technique was used to examine the solvent effects of ethyl 5-methyl-3 phenyl-1H-indole 2-carboxylate [5-MPIC]. Different solvents were used to record 5-MPIC’s absorption and emission spectra at room temperature (300 K). The ground state and excited state dipole moments were estimated experimentally using Lippert’s, Bakshiev’s and Kawaski Chamma Viallet’s equations. The HOMO-LUMO gap and MEP map were also estimated theoretically by using B3LYP/6-31+G (d, p) basis set of Gaussian 16 w program. Dipole moments of excited states reveal a clear polarity difference between the ground and excited states.

Investigation of the Transient Field at High Velocities by magnetic-moment measurements in 74Ge and 70Zn

The advent of radioactive beams at large experimental facilities has moti- vated extensive research work on the expansion of techniques to accommodate higher ion velocities. The application of the Transient Field technique in measuring magnetic moments of excited states in energetic nuclei is investigated at the INFN-LNS in Catania by means of re-measuring the g(2+1 ) factors in 74Ge and 70Zn. The description of the experiment method and some preliminary angular correlation results are presented.

Magnetic moment measurements – extending isotopic chains beyond the stable elements

The magnetic moments in many isotopic chains have been systematically measured using the transient field technique on beams of separated isotopes excited in inverse kinematics. Such experiments have provided insight into how the structure of nuclei evolves by successively adding nucleons. Since naturally occurring isotopic chains are relatively short, efforts are underway to make unstable isotopes available. In limited cases the use of an a-particle transfer to beam projectiles has been successfully employed in measurements on unstable nuclei. In this investigation beams of 78Kr and 86Kr were used to measure magnetic moments of excited states in the unstable 82 Sr and 90 Sr nuclei utilizing the transfer of an α particle from 12 C nuclei in the target.

Self-consistent calculations of quadrupole moments of the first 2+states in Sn and Pb isotopes

A method of describing static moments of excited states and transitions between excited states is formulated for nonmagic nuclei within the Green's function formalism. Quadrupole moments of the first 2${}^{+}$ states in tin and lead isotope chains are calculated self-consistently using the energy density functional by Fayans et al. [Nucl. Phys. A 676, 49 (2000)]. Reasonable agreement with available experimental data is obtained. Quadrupole moments of unstable nuclei including ${}^{100}$Sn and ${}^{132}$Sn are predicted. A nontrivial dependence of the quadrupole moments on the neutron excess is found which can be traced to the negative proton contributions.

Excited state characteristics of acridine dyes: acriflavine and acridine orange

The magnitude of the Stokes shift (frequency shifts in absorption and fluorescence spectra) is observed on changing the solvents and further has been used to calculate experimentally the dipole moments (ground state and excited state) of acriflavine and acridine orange dye molecules. Theoretically, dipole moments are calculated using PM 3 Model. The dipole moments of excited states, for both molecules investigated here, are higher than the corresponding values in the ground states. The increase in the dipole moment has been explained in terms of the nature of the excited state. Acriflavine dye overcomes the non-lasing behaviour of acridine orange due to quaternization of the central nitrogen atom.

Energies and Dipole Moments of Excited States of Ozone and Ozone Radical Cation Using Fock Space Multireference Coupled-Cluster Analytical Response Approach

Using the Fock space multireference coupled-cluster (FS-MRCC) analytical linear response approach, we report the dipole moments of low-lying singlet and triplet excited states of ozone. The low-lying singlet and triplet excited states are calculated at the ground-state geometry and at the adiabatic geometry for the 1A2 and 1B1. For comparison we also calculate at the ground-state geometry the dipole moments of the 1A2, 1B1 and 1B2 using multireference configuration interaction (MRCI) with a bigger VQZ basis and complete active space. We also report as by-product the excitation energy values in the singles and doubles approximation. At the ground-state geometry we also report the energy and the dipole moments of the 2A1, 2A2 and 2B1 states of the ozone radical cation. The energy of the ozone cation radical is compared with the other correlated approaches. It matches well with the experimental values.

Measurement ofgfactors in84,86Zrand87Nbby the recoil distance transient fieldγ-γcoincidence technique

Magnetic dipole moments of excited states in ${}^{84}\mathrm{Zr}$ and the $N=46$ isotones ${}^{86}\mathrm{Zr}$ and ${}^{87}$Nb were measured. The recoil distance transient field method, which is a coincidence technique combining the recoil distance and the transient field methods, was applied. The measurement was performed such that it was sensitive only to those excited states which were populated a few picoseconds after the nuclear reaction. The influence of unobserved continuum feeding on the measured precession angles can thus be neglected. The results are compared with the values obtained using other experimental techniques and with shell model calculations.

A class IV charge model for molecular excited states

We present a new parameterization for calculating class IV charges for molecules containing H, C, N, O, F, Si, P, S, Cl, Br, and I from wave functions calculated at the intermediate-neglect-ofdifferential-overlap-for-spectroscopy (INDO/S) level. First we readjust the oxygen parameters in INDO/S on the basis of electronic excitation energies; this yields a new set of parameters called INDO/S2. Then we parameterize the charge model. The new model, called charge model 2 for INDO/S2 (CM2/INDO/S2), is parameterized against the most accurate available data from both ab initio and experimental sources for dipole moments of ground and excited electronic states. For a training set containing 211 dipole moments of molecules in their ground states and 33 dipole moments of molecules in their first excited states, the CM2/INDO/S2 model leads to a root-mean-square (rms) error in dipole moments of 0.26 D for ground states and 0.40 D for the excited states. The new model, INDO/S2 with CM2, systematically improves the n→π* excitation energies and the dipole moments of the excited states of carbonyl compounds. We also parameterized a CM2 model for the standard INDO/S model (CM2/INDO/S), which predicts quite accurate dipole moments for ground states with an rms error of 0.24 D.

Measurements of lifetimes and magnetic moments inA ≈ 90 nuclei with EUROBALL Cluster detectors

MassA ≈ 90 nuclei with several valence nucleons outside the doublymagic100Sn core are an ideal testing ground for the validity of the spherical shell model. Electromagnetic decay properties as well as magnetic dipole moments of excited states are the key quantities revealing the structure of the wave functions and themechanisms responsible for strong dipole sequences. The present article discusses by means of two examples the advantages of employing the most recent developments both concerning detector technology and experimental methods.

Alignment and orientation in atomic collisions

Recent experimental and theoretical studies of alignment, orientation and dipole moments of excited states formed in atomic collisions for simple systems are reviewed. We also review the studies of the dependence of electron capture cross sections on the magnetic quantum numbers of the initial target states. The propensity rule involving the magnetic quantum numbers in atomic collisions is also examined.

Finite-element multiconfiguration Hartree-Fock calculations of the atomic quadrupole moments of excited states of Be, Al, In, Ne, Ar, Kr, and Xe.

The atomic quadrupole moments Q zz of Be(2s2p; 3 P 2 ), Al(3p; 2 P 3/2 ), In(5p; 2 P 3/2 ), Ne(2p 5 3s 3 P 2 ), Ar(3p 5 4s; 3 P 2 ), Kr(4p 5 5s; 3 P 2 ), and Xe(5p 5 6s; 3 P 2 ) have been calculated using a finite-element multiconfiguration Hartree-Fock method. The obtained Q zz (Be) of 2.265 a.u. agrees with previously calculated values

Vibrational dependence of the anisotropic intermolecular potential of Ar–HF

A new intermolecular potential for Ar–HF is obtained by fitting to results from high-resolution microwave, far-infrared, and infrared spectroscopy. The new potential, designated H6(4,3,2), is a function of the diatom mass-reduced vibrational quantum number η=(v+ (1)/(2) )/(μHX)1/2 as well as the intermolecular distance R and angle θ, and has 22 adjustable parameters. It reproduces all the available spectroscopic data for levels of Ar–HF correlating with HF, v=0, 1, and 2, and DF, v=0 and 1. The H6(4,3,2) potential is qualitatively similar to previous potentials, with a linear Ar–H–F equilibrium geometry and a secondary minimum at the linear Ar–F–H geometry. Compared to the potential of Nesbitt et al. [J. Chem. Phys. 90, 4855 (1989)], obtained from spectra of Ar–HF (v=1), the H6(4,3,2) potential is rather deeper near the equilibrium geometry (Ar–H–F), but shallower around the secondary minimum (Ar–F–H). The absolute well depth increases by 19 cm−1 between HF v=0 and v=1. The vibrationally averaged induction energy is calculated to be substantially (8.1 cm−1 ) greater for v=1 than for v=0, and is responsible for most of the observed red shift in the complex. Predictions of additional spectroscopic properties that would test the new potential are given, including far-infrared and overtone spectra of Ar–DF and dipole moments of excited states of Ar–HF and Ar–DF.

Magnetic Moments of Excited States in the Ca-Region

Magnetic Moments of Excited States in the Ca-Region

Magnetic moments of excited states in the stable chromium isotopes.

The g factors of the first ${2}_{1}^{+}$ states in $^{50}\mathrm{Cr}$ and $^{54}\mathrm{Cr}$ have been measured by the perturbed angular correlation/transient field technique. The results, g(${2}_{1}^{+}$, $^{50}\mathrm{Cr}$)=+0.45(15) and g(${2}_{1}^{+}$, $^{54}\mathrm{Cr}$)=+0.53(12), are compared to shell model calculations.

Muonic x-ray study ofHg199andHg200

Muonic x-ray spectra have been measured for $^{199}\mathrm{Hg}$ and $^{200}\mathrm{Hg}$. From the data we have determined model-independent charge radii and isomer shifts of certain excited nuclear states and have inferred spectroscopic quadrupole moments of excited states for both isotopes. The quadrupole moment of the lowest $\frac{5}{{2}^{\ensuremath{-}}}$ state in $^{199}\mathrm{Hg}$ is found to be positive, in agreement with previous muonic-atom data but in disagreement with a recent M\"ossbauer study. $B(E2)$ values of low-lying excited states have been determined for $^{199}\mathrm{Hg}$. An $E1$ muonic-nuclear resonance has been discovered in $^{200}\mathrm{Hg}$.NUCLEAR STRUCTURE $^{199,200}\mathrm{Hg}$; measured muonic x-ray spectra; deduced monopole and quadrupole charge parameters, isomer shifts.

Measurement of the dipole moments of excited states and photochemical transients by microwave dielectric absorption

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMeasurement of the dipole moments of excited states and photochemical transients by microwave dielectric absorptionRichard W. Fessenden, Paul M. Carton, H. Shimamori, and Juan C. ScaianoCite this: J. Phys. Chem. 1982, 86, 19, 3803–3811Publication Date (Print):September 1, 1982Publication History Published online1 May 2002Published inissue 1 September 1982https://doi.org/10.1021/j100216a020RIGHTS & PERMISSIONSArticle Views317Altmetric-Citations81LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Electronuclear energy weighted sum rules and the quadrupole moments of excited states of nuclei

Abstract Using the partial sums of the angular momentum projected energy weighted sum rules, relations are obtained for the quadrupole moments of the 2+ excited states of even nuclei. Assuming that the partial sums for a three-level system, consisting of the ground state, 21+ and 22+ states, exhaust their respective sum rules to the same extent, the quadrupole moments extracted are found to agree very well with experimental results for a wide variety of nuclei. The effect of considering more 2+ states is discussed.

Molecular Rydberg transitions: Field effects in the vacuum ultraviolet

Magnetic-field (Zeeman) and electric-field (Stark) effects provide much information on excited electronic states. The experimental approach is similar in both cases: an external field is imposed; the changes of energy and intensity of a spectroscopic line are measured; and these changes are used to infer excited- and ground-state properties. Since the field-induced changes are small (e.g. ΔE≈1−10cm −1), the technique is applicable only to sharp line-spectra (i.e. to atoms and small molecules). Technological advances have now made possible the measurement of subtle shape-changes, a circumstance which opens up field-effect studies of the broad bands which characterize large molecules. Such magnetic field 1,2) and electric field 3,4) studies exist. The techniques are commonly referred to as “magnetic circular dichroism” (MCD) and “electrochromism”, respectively. We prefer the name “electric linear dichroism” (ELD) for the latter technique. ELD 5,6) and MCD 7,8,9) studies in the VUV are also available. Our interest resides in molecular Rydberg states, which usually lie in this region. These states, at low-energy are heavily mixed with valence states and, at high-energy, are precursors to cationic states. Our intent is to categorize these states and to understand the transition from strong core-coupling (valence) to weak core-coupling (Rydberg) to zero core-coupling (continuum). • MCD studies of spherical and symmetric-top molecules should yield: • (a) the electronic magnetic moment of excited states, whence one can infer angular momentum,. • (b) the mechanism which confers “allowedness” on nominally-forbidden transitions (e.g. vibronic coupling), • (c) the operative spin-orbit coupling regime (e.g. various Hund cases, Ω c ω ,etc.), • (d) a magnetic-field-induced intensity, and detection of otherwise unobservable transitions. ELD studies should yield: • (d) field-induction of intensity, • (e) electric-dipole transition polarization for C mv ( m⩾2) molecules, • (f) permanent electric dipole moments of excited states, whence their charge transfer nature may be inferred, • (g) electric polarizability which, for H-like atoms, is proportional to r 3 (or n 6) and is a measure of orbital size (and, hence, valence/Rydberg mixing).

Shell model calculations of two to four identical-“particle” systems near 208Pb

The structure of the nuclei 204–206Pb, 210–212Pb, 210Po, 211At, and 212Rn is studied in terms of conventional nuclear shell models. An inert 208Pb core is assumed, and active particles (holes) are distuibuted in the low-lying single-particle (hole) orbits. Experimental single-particle energies are used for the one-body part of the effective residual interaction. Realistic interaction matrix elements developed for this mass region by Kuo and Herling are used for the matrix elements of the two-body part of the residual interactions. As much as possible, other effective one-body operators for electromagnetic observables are derived from experimental data on the single-particle (hole) nuclei 207Pb, 209Pb, and 209Bi. Observables treated are ground state binding energies, excitation energies, strengths for one- and two-particle transfers, and E2 and M1 observables. Generally, excellent agreement is found. The configuration mixing calculations do not remove anomalies in the magnetic moments of excited states in 206Pb and 212Rn. Many states in these nuclei are predicted by the models which have not been observed as yet. It is found that a truncation scheme for doubly even nuclei treated here in which only seniority-0 and seniority-2 states are allowed is potentially very useful.