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Usually, the optical transition properties of trivalent rare earth (RE) ions in transparent hosts can be quantitatively investigated in the framework of Judd–Ofelt theory. A standard and commonly accepted calculation procedure based on the absorption spectrum has already been established. However, it is hard to assess the optical transition properties of trivalent RE ions doped in powdered and film materials owing to the difficulty in the absolute absorption spectrum measurements. In this work, we proposed a new route to calculate the Judd–Ofelt parameters of trivalent RE ion-doped materials in any morphological and shaped forms. In this method, the fluorescence decay values bridging the radiative transition rates and the Judd–Ofelt parameters were used. As an application example of the proposed Judd–Ofelt calculation method, the Judd–Ofelt parameters of Er3+ in NaYF4 were calculated via the proposed route, and it was found that the obtained results are in reasonable accordance with those derived from other routes. It was also proved that this proposed Judd–Ofelt calculation method is a practicable and effective route for evaluating optical transition properties of trivalent RE ions in non-transparent hosts as long as the fluorescence decay values can be measured.

It is difficult to calculate the Judd-Ofelt (J-O) parameters for trivalent rare earth (RE)-doped powders due to the unavailable absorption spectrum that is necessarily used in the conventional J-O calculation procedure. In this study, a universal method starting from the diffuse-reflection spectrum for calculating the J-O parameters of RE3+-doped powdered samples was proposed. In this proposed method, by taking the Kubelka-Munk function into account, the absorption cross-section spectrum was derived from the diffuse-reflection spectrum in the RE3+-doped powdered sample using the connection between the absorption cross section and the radiative transition rate of RE3+. Then, the J-O parameters might be calculated from the absorption cross-section spectrum via the traditional J-O calculation technique. The NaYF4:Er3+/Yb3+ and NaYF4:Er3+ phosphors were prepared via an auto-combustion-assisted fluoridation technique, and the J-O calculation was carried out for the obtained samples. The obtained J-O parameters were compared with those reported in the literature and also verified by comparing the calculated radiative transition lifetimes with the experimental values. Finally, it was deduced that the proposed J-O calculation route was practicable.

Inner-shell excitation energy levels, and radiative and Auger transitions of the 1s2s22p2, 1s2s22p3p, 1s2s2p3, 1s2p4, and 1s2p33p 2,4L (L = S, P, D) resonances for B-like nitrogen are calculated using the saddle-point variation and saddle-point complex-rotation methods. The first-order perturbation theory is used to calculate relativistic and mass polarization corrections. Present autoionization energy levels, radiative transition rates and wavelengths, Auger rates, and Auger electron energies for these resonances agree well with theoretical and experimental data available in the literature, and will provide valuable background data for astrophysics and plasma physics in future.

Radiative transition decay width for was calculated by using twisted mass lattice quantum chromodynamics gauge configurations in this preliminary study. The simulation has been performed on lattices with lattice spacings and lattice size (Ens.C 1), and and lattice size (Ens.B 1) respectively. In this simulation, we have considered the parity mixing effect by using variational method. The calculated central value for the decay width is closer to the experimental data than that in previous lattice studies.

Reducing the radiative transition’s time constant from thousands of years to a fraction of a second could benefit quantum information schemes.

Luminescence generated by a plate-impact-induced shock wave has been detected from a Ce-doped phosphor powder, Ce3+:Y3Al5O12. The observed luminescence spectrum shows two strong bands in the visible region: one at ∼410 nm and the other at ∼530 nm. The second band is very similar to the well-known luminescence band of Ce:YAG corresponding to the T2g → 2F transition, but the first band is hardly observed in the photoluminescence spectrum. One possible mechanism for the first band is the radiative transition from the higher energy excited level of Ce3+ to the ground level, namely Eg → 2F.

Radiative transition probabilities ($A$ values) are computed for the Fe xvii $L$-shell lines in a Breit-Pauli configuration-interaction method with the autostructure atomic structure code. It is shown that, by carefully taking into account the fine-tuning of the relativistic coupling and $2p$-orbital relaxation, the measured $A$ values of the $M1$ and $M2$ lines and, for the first time, the low $f(3C)/f(3D)$ oscillator-strength ratio are satisfactorily reproduced by the theory. The present ratio $f(3C)/f(3D)=2.82$ compares well with the measurement of $2.61\ifmmode\pm\else\textpm\fi{}0.23$ by x-ray laser spectroscopy.

We have reported the level energies and radiative transition (E1, E2 and M1) parameters, such as wavelengths, transition rates, oscillator strengths and line strengths for some levels over the ionization limit of Ne III (oxygen-like). The calculations have been performed using the general-purpose relativistic atomic structure package (GRASP) based on the fully relativistic multiconfiguration Dirac-Fock (MCDF) method. The results obtained have been compared with the available theoretical and experimental values in the literature.

Reducing the radiative transition’s time constant from thousands of years to a fraction of a second could benefit quantum information schemes.

A Lorentz invariant formalism for quasi-classical description of electromagnetic radiation from a neutral spin 1/2 particle with an anomalous magnetic moment moving in an external electromagnetic field is developed. In the high symmetry fields, for which analytical solutions to the Bargmann--Michel--Telegdi equation are known, the so called self-polarization axes, i. e. directions of preferred polarization of particles in the radiation process, are found. Expressions for the radiative transition probability and spectral-angular distribution of the radiation emitted by a polarized particle are obtained in the fields under consideration., Revised version. 15 pages, 1 figure, latex

Accurate potential energy curves, transition moments, spectroscopic constants, radiative transition probabilities, and lifetimes for the states X²sigma+ and A²pi of BeF, MgF and CaF are reported using high level calculations. Diagonal transitions dominate for the A²P ® X²sigma+ system. Radiative lifetimes for nu' = 0 are predicted to be 6.81 ns, 7.16 ns and 19.48 ns, respectively for BeF, MgF and CaF. The result calculated for the CaF molecule are in excellent agreement with the experimental result equal to 21.9±4.0 ns.

A comprehensive study on the thermal stability and spectroscopic properties of Er3+/Yb3+-codoped Al(PO3)3-based fluorophosphate glasses is reported of the 1.5μm fibre amplifiers in this paper. From optical absorption spectra, the Judd–Ofelt parameters of Er3+ in the glasses and several important optical properties, such as the radiative transition probability, the branching ratio and the spontaneous emission probability, have been calculated by using Judd–Ofelt theory. The fluorophosphate glass exhibits broadband near-infrared emission at 1.53 μm with a full width at half-maximum over 63nm and a large calculated stimulated-emission cross-section of 6.85×10−21cm2.

Laboratory formation of four isomers of C5H2 molecule is reported and detection of the ring-chain isomer (isomer 1) of C5H2 in cosmic objects has been suggested. For identification of a molecule in cosmic objects, one of the required input data is EinsteinA-coefficients (radiative transition probabilities) for the molecule. Here, we report EinsteinA-coefficients for electric dipole transitions in the ring-chain isomer of C5H2 among the rotational levels of the ground electronic and ground vibrational states up to 21 cm−1.

Accurate potential energy curves, transition moments, spectroscopic constants, radiative transition probabilities, and lifetimes for the states X 3 Σ − , (1) 3 Π , and (2) 3 Σ − of BeC, MgC, and CaC are reported using high level calculations. Diagonal transitions dominate for the (2) 3 Σ − → X 3 Σ − system, with band origins falling at 745, 648, and 770 nm, and an intensity ratio of 6,3,1, respectively for BeC, MgC, and CaC. Radiative lifetimes for v ′ =0 are equal to 0.48, 1.45, and 3.29 μs for the state (2) 3 Σ − , and equal to 13.57, 10.44, and 9.62 μs for the state (1) 3 Π for BeC, MgC, and CaC.

Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of root s = 4.23, 4.26, and 4.36 GeV, we observe e(+)e(-) -> pi(0)pi(0)h(c) for the first time. The Born cross sections are measured and found to be about half of those of e(+)e(-) -> pi(+)pi(-)h(c) within less than 2 sigma. In the pi(0)h(c) mass spectrum, a structure at 4.02 GeV/c(2) is found. It is most likely to be the neutral isospin partner of the Z(c)(4020)(+/-) observed in the process of e(+)e(-) -> pi(+)pi(-)h(c) being found. A fit to the pi(0)h(c) invariant mass spectrum, with the width of the Z(c)(4020)(0) fixed to that of its charged isospin partner and possible interferences with non-Z(c)(4020)(0) amplitudes neglected, gives a mass of (4023.9 +/- 2.2 +/- 3.8) MeV/c(2) for the Z(c)(4020)(0), where the first error is statistical and the second systematic.

Energy levels and radiative rates for transitions among the 107 fine-structure levels belonging to the (1s 2 2s 2 2p 6 ) 3s 2 3p 6 3d 10 , 3s 2 3p 6 3d 9 4, 3s 2 3p 5 3d 10 4, and 3s3p 6 3d 10 4 configurations of Ni-like ions with 60 < Z < 90 have been calculated using the GRASP code. The collision strengths (Ω) have also been computed for transitions in Gd XXXVII at energies below 800 Ryd, using the DARC code. Resonances have been resolved in a fine energy mesh in the threshold region, and excitation rate coefficients have been calculated for transitions from the ground level to excited levels at tem peratures below 2500 eV. These have been compared with those available in the literature, and enhancement in the values of rates, due to resonances, has been observed up to an order of magnitude for some of the transitions.

Measurements at high target pressures of the radiative lifetime and the collisional deactivation of the N 2 C state are currently being published. It is shown in the present Comment that such measurements may yield too small deactivation rates in view of reverse transfer effects.

We present an experimental determination of the 2p3dð 1 P o Þ! 1s3dð 1 D e Þ x-ray line emitted from He-like Si, S, and Cl projectile ions, excited in collisions with thin carbon foils, using a high-resolution bent-crystal spectrometer. A good agreement between the observation and state-of-the-art relativistic calculations using the multiconfiguration Dirac-Fock formalism including the Breit interaction and QED effects implies the dominance of fluorescent decay over the autoionization process for the 2p3dð 1 P o Þ state of He-like heavy ions. This is the first observation of the fluorescence-active doubly excited states in He-like Si, S, and Cl ions.

The relative intensities of dielectronic satellite lines determined by radiative transition probabilities and autoionization rates are calculated for the transitions 2lnl' – 1snl'', 2lnl' – 1s2l (n = 4–5, l' = 0–3, l'' = 0–3, l = 0–1) in He-like ions and for the transitions 1s2lnl' – 1s2nl'', 1s2lnl' – 1s22l (n = 4–5, l' =0–3, l'' = 0–3, l = 0–1) in Li-like ions, for all Z = 5–54, using the perturbation theory method (Z-expansion). Relativistic effects are taken into account using the Breit–Pauli operators. The asymptotic dependence on n of the energy matrix is discussed for 2lnl' and 1s2lnl' autoionizing states. The intermediate coupling coefficients obtained after diagonalization of the energy matrices are also studied. It was observed that these coefficients change very sharply with n and Z due to a redistribution of the contributions of relativistic and correlation effects. As a result, all other atomic characteristics (radiative and nonradiative transition rates, branching ratios, and relative intensity factor) display nonmonotonic Z- and n-dependencies with maxima and minima. PACS Nos.: 32.80D, 31.20G, 31.30J, 31.50

The total radiative transition probabilities of rovibronic levels of B, C, B 0 and D states of molecular hydrogen are calculated with emphasis on the dissocia- tion fraction and the kinetic energy released in the con- tinuum radiation process. The mixing percentages of B, C, B 0 and D adiabatic states are also given. The data are calculated with the detailed transition probabilities ob- tained by Abgrall et al. (1993, 1994). We have included, in the present analysis, results obtained by using a recent ab initio transition moment for D X which comprises a larger range of internuclear distances. The related data on individual transition probabilities may be obtained on request.

Transition moment functions involving the ground electronic state and various excited doublet states of the BeH molecule are reported using highly correlated wavefunctions generated by the multi-reference single and double excitations configuration interaction approach. Radiative transition probabilities and lifetimes for the band systems A 2 Π –X 2 Σ + and C 2 Σ + –X 2 Σ + are also presented. Radiative lifetimes are predicted to be 81 and 163 ns for the first vibrational level of the A 2 Π and C 2 Σ + states, respectively. The strongest transitions should correspond to the (0–0) and (0–8) bands of the A 2 Π + –X 2 Σ + and C 2 Σ + –X 2 Σ + systems.

In this work, two-photon-excited photoluminescence dynamics in ZnS functionalized ZnO nanotetrapods were investigated. Comparing to the bare ZnO nanotetrapods, the emission peaks of the ZnO/ZnS nanotetrapods red-shifted by 5–10 nm, and the photoluminescence intensity and lifetime of the ultraviolet exciton radiative transition increased more than 20 times due to the passivation effect of the core/shell structure.

Radiative transition probabilities have been calculated for the magnetic dipole (M1) and electric quadrupole (E2) transitions connecting the 47 metastable energy levels in the 3d 8 , 3d 7 4s and 3d 6 4s 2 configurations in Co II. The most important configuration interaction (CI) and relativistic effects have been taken into account in the computations carried out with the help of the relativistic Hartree-Fock (HFR) method combined with a semi-empirical optimization of the radial parameters.

An earlier measurement on the ${4}^{+}$ to ${2}^{+}$ radiative transition in $^{8}\mathrm{Be}$ provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. This Letter reports a more elaborate and precise measurement for this transition, via the radiative capture in the $^{4}\mathrm{He}+^{4}\mathrm{He}$ reaction, improving the accuracy by about a factor of 3. Ab initio calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and ab initio calculations.

By applying AUTOSTRUCTURE code, the energies and transitions for allowed (El) and forbidden (E2, M1, and M2) lines for low-lying configurations in magnesium-like tungsten (W62+) are studied. The electron correlation and relativistic effects are included in computations. Good agreement between our results and available other results are found. The data for E2, M1 and M2 besides some El transitions for low-lying levels are presented for the first time.

New radiative transition probabilities have been calculated for forbidden lines of astrophysical interest in Ni I and Ni II. The accuracy of the transition probability scales is established on the basis of two independent calculations performed with the approximately relativistic Hartree-Fock and SUPERSTRUCTURE codes. Both physical models take into account the most important configuration interaction (CI) and relativistic effects.

Radiative transition probabilities have been calculated for states within the 3d 6 conguration of Fe III. Magnetic dipole (M1) and electric quadrupole (E2) transition probabilities have been obtained using average energies, electrostatic and spin-orbit integrals adjusted so as to t the observed energy levels. The most important conguration interaction (CI) and relativistic eects were included explicitly in the calculations, using the relativistic Hartree-Fock (HFR) method due to Cowan. The present work represents a renement of previous monocongurational calculations of transition probabilities for forbidden lines of astrophysical interest in Fe III.

It is shown that the calculation of atomic constants by some versions of the multi-configurational method, or its relativistic generalizations, violates the principles of a consistent theory based upon the quantum electrodynamic (QED) approach. The consequences of this violation for the radiative transition probabilities are under investigation. We obtained the probabilities of innershell radiative transitions in Ne-like argon and iron in the lowest approximation of a consistent theory. These results are compared with the corresponding data from some recent publications.

Low-lying electronic states (X2, A2+, a4, B2, b4, C2, F2-, E2+ and D2) of the 6Li32S molecule are computed at the aug-cc-pV5Z/MRCI level. The potential energy curves are presented for these states; the corresponding spectroscopic constants are reported. Electronic transition moment, Einstein coefficients, Frank-Condon factors and radiative lifetimes for the A2+-X2, B2 -X2, C2 -X2 systems are calculated. The balanced distance between two nuclei, harmonic frequencies and inertia moment of ground state X2 are predicted in this paper, and they are in accordance with their corresponding experimental data. The balance distances between the two nuclei in the electronic states of b4, C2, D2 are all longer than 4 , so they are very unstable. The D2 electronic state will dissociate to Li+ ion and S- ion: they are far from each other. The electronic transition dipole moment, Einstein coefficient, Franck-Condon factor and radiative lifetime in transition from lowest excited A2+ state to ground state X2 are predicted in this paper. The electronic transition dipole moments from three low lying electronic state A2+, B2 and C2 to the ground state X2 are calculated at the aug-cc-pV5 Z/MRCI level. The results show that the electronic transition dipole moment of A2+X2 has a small positive value while the nucleus distance is short, and rapidly decreases down to a small negative value with the nucleus distance increasing to around balance distance. Then it is stable about zero value while the nucleus distance continually increases. The electronic transition dipole moment of B2 X2 has a small negative value (which is larger than that of A2+ X2) at a short nucleus distance, and rapid increases up to a small positive value with the nucleus distance increasing to about balance distance. Then it slows down to zero while the nucleus distance increases to about 4. Finally it turns stable about zero value while the nuclei distance continually increases. The electronic transition dipole moment of C2 X2 is more sophisticated, but it has a large value than other two transitions. So the low-lying electronic state A2+ is stabler than B2, and B2 is stabler than C2 . The results also show that the ground state X2 and the lowest excited state A2+ have similar IR frequencies, their difference is within 8 cm-1, so they cannot be distinguished by IR spectrum. The A2+ has a balanced distance about 0.076 shorter than ground X2, which implies that A2+ has stronger chemical bond than ground X2 .

A full relativistic configuration interaction (RCI) calculation of transition energies and radiative transition rates involved in O III Bowen fluorescence mechanism is presented. The calculated ratios of transition line intensities are in good agreement with the observed ratios. The discrepancies between the RCI calculation and prediction based on LS coupling scheme show that a delicate balance between the electron correlations and the spin-orbital interactions should be important even for the low-Z O III ion.

The technique of optical-optical double resonance spectroscopy is used to study the radiative lifetimes of the Cl 2 ion-pair states from the fluorescence decays. This experiment allows us to classify the six gerade states correlating to the lowest asymptote Cl − ( 1 S)+Cl + ( 3 P) into two groups from the fluorescence lifetimes. One involves the four spin-orbit components of the 3 Π g state, O + g ( 3 P 2 ), O − g ( 3 P 2 ), 1 g ( 3 P 2 ), and 2 g ( 3 P 2 ), showing short lifetimes of 4–5 ns. The other includes those of 3 Σ − g with lifetimes almost an order of magnitude longer; 44.6±0.5 ns for 0 + g ( 3 P 0 ) and 73.8±3.0 ns for 1 g ( 3 P 1 ).

The radiative decay of [Formula: see text] is considered in a field theoretic quark model. It is found that the size of the baryon plays significant role and the branching ratio of the decay is highly suppressed by the order of factor 10−8.

Time‐resolved photoluminescence has been used to study the decay of photoexcited carriers in bulk InSb at 2 K. The recombination occurs as a two step process exhibiting a fast and a slow decay. The fast decay, corresponding to band‐to‐band recombination, occurs with a time constant of the order of 60 nsec and is accompanied by time‐resolved band gap renormalization. The slow process, identified in the band‐to‐acceptor photoluminescence, occurs with a time constant of 3.8 μsec. We show that this is in excellent agreement with the theoretical value of the band‐to‐acceptor radiative transition rate. These results help reconcile discrepancies that have long existed between conventional photoluminescence measurements and time‐resolved photoconductivity measurements.

A new method for the determination of intrinsic lifetimes of excited species participating in a complex mechanism is presented. This method is independent of the mechanism itself, and only requires that the interacting species maintain their identity and exist in a known number. The method is applied to the determination of the excimer lifetime of pyrene in cyclohexanol from 25 to 85°C. An activation energy of 12±1 kJ mol −1 is calculated from the reciprocal excimer lifetime Arrhenius plot.

MgO molecules have been produced in X 1 Σ + , a 3 Π, and a 1 Π dark states by the Mg ( 1 S 0 ) + N 2 O (X 1 Σ + ) reaction in an experiment performed with pulsed, crossed, supersonic molecular beams. Analysis of fluorescence decays following pulsed dye-laser excitation of the MgO reaction product has resulted in radiative lifetime determinations of the B 1 Σ + v =0–3, d 3 Δ and D 1 Δ states. The following values have been found at 95% confidence level: B 1 Σ + state, τ υ=0 =21.5±1.8 ns, τ υ=1 =21.9±2.1 ns, τ υ=2 =21.7±2.0 ns, τ υ=3 =21.5±3.2 ns; d 3 Δ state, τ υ=0 =7.8±1.8 ns; D 1 Δ state, τ υ=0 =4.3±1.0 ns.

On the bais of two programs, calculations are carried out for energies, probabilities of radiative transitions and nonradiative decays, and lifetimes of levels of two-electron systems 2l.4l′. The results of the two calculations are compared for a wide range of Z. Possible channels of radiative transitions and nonradiative decays are discussed. Their relative contribution to the total probability is evaluated. This evaluation is compared with data obtained by calculations, on the basis of which a conclusion is made about the contribution of correlation and relativistic effects. The Z-dependences are investigated for each of the parameters under consideration. A comparison is made with the results of other calculations.

When the collisional dynamics of two states under consideration for a radiative transition is different, the polarization and population relaxations in gas phase at low pressure are governed by four-, instead of three-, coupled Bloch-type equations. The general transient solutions of these four-coupled equations are solved by using the Laplace transformation technique. It has been found that an additional exponential term appears because of the effect. This is also responsible for the non-exponential character in the decay signal of a transient microwave pulse experiment, besides other factors reported earlier.

We have studied the Phillips (A 1∏u–X 1∑+g ) band system of C2 in order to help resolve the discrepancy between the best theoretical lifetimes and those deduced recently from laser‐induced fluorescence (LIF) studies. Our calculated lifetime for the A 1∏u(v’=0, J’=1) state is 13.0 μs, in excellent agreement with the recent calculations of ONeil et al., but considerably shorter than the direct experimental measurements. A measure of the accuracy of the complete‐active‐space self‐consistent‐field (CASSCF) multireference configuration‐interaction (MRCI) results in this work is obtained by a series of calibration calculations. Convergence in the n‐particle space is demonstrated by comparison with full configuration interaction calculations in a double‐zeta plus polarization basis, while the convergence of the one‐particle basis set is demonstrated by systematically expanding the one‐particle basis set up through g angular momentum functions. Furthermore, a coupling of the one‐ and n‐particle spaces is shown to...

Calculations using large atomic natural orbital (ANO) basis sets and high levels of correlation treatment are employed to determine the radiative lifetime for the v =1–5 levels of the X 1 Σ + state of NO + . The theoretical lifetimes, which agree well with previous theoretical estimates, are estimated to be accurate to 5%. These results strongly suggest that the recently measured radiative lifetimes for the v =2 and 3 levels are in error.

A theoretical description of the electronic states of the SBr radical at a high level of correlation effects treatment is presented for the first time. Most of its potential energy curves have a repulsive nature, but a set of bound (2)Pi states should provide a means for the experimental characterization of this species. The ground state can support over 40 vibrational states, but transitions from the 2 (2)Pi state, with a very shallow well (four levels), should have intensities spread over a maximum around v(")=10; lower vibrational levels can only be accessed for transitions from two high-lying Rydberg states. A whole set of spectroscopic constants, including vibrationally averaged spin-orbit coupling constants, and radiative transition probabilities and lifetimes quantify the theoretical description, thus supplying reliable results to guide the experimental investigation of this species.

The strong resonant pumping in a Nd:YAG small sphere modifies the radiative transition possibility distribution between two transition energy levels in the material. Some new emissions which cannot be seen in the bulk material are found for the first time.

COLOQ 7 " 7ème COloque sur les Lasers et l'Optique Quantique " (Rennes, France, september 2001); National audience; Nous proposons une méthode simple pour obtenir les fonctions de base des représentations irréductibles. Une procédure automatisée est proposée pour exprimer les opérateurs de projection comme combinaisons d'harmoniques sphériques. L'application de cet automate permet l'obtention des harmoniques cubiques (fonctions associées à la symétrie cubique) à partir desquelles les fonctions propres des bandes de conduction et de valence dans GaAs sont exprimées.

The emission and excitation spectra of four phenylated [70] fullerenes, C 70 Ph 4 , C 70 Ph 6 , C 70 Ph 8 , and C 70 Ph 10 in cyclohexane and toluene solutions have been measured. The fluorescence spectra and related excited state properties are found to depend strongly on the number of attached phenyl groups, but with no systematic trends. Quantum yields and fluorescence lifetimes were measured for C 70 Ph 6 , C 70 Ph 8 , and C 70 Ph 10 , allowing the determination of S 1 → S 0 radiative transition rates k R . It is found that k R for C 70 Ph 10 is about six times larger than for the other compounds. This is consistent with measured absorbtivities for these compounds. The particular character of C 70 Ph 10 is also manifested by its higher intersystem crossing rate k ISC .

(ENG)Radiative transition probabilities for 190 lines arising from the ns ²S₁/₂, np ²P₁/₂,₃/₂, nd ²D₃/₂,₅/₂, nf ²F₅/₂,₇/₂, and 6p² (⁴P₁/₂,₃/₂,₅/₂, ²D₃/₂,₅/₂, ²P₁/₂,₃/₂, and ²S₁/₂) levels of Pb(II) have been calculated. Lifetimes of the above mentioned levels have been determined from the present transition probabilities. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree–Fock calculations. For the IC calculations, we use the standard method of least-square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities and excited states lifetimes are presented and compared with the experimental results present in the literature and with other theoretical values. There is generally good agreement between our values and the experimental data available. Analysis of the interaction shows that the level ⁴P₅/₂ of the 6s6p² configuration presents a large contribution to the ²D₅/₂ level of the 6s²6d configuration. This result explains the good agreement between our result and the experimental values obtained to the observed as the 6s6p² ⁴P₅/₂ – 6s²5f²F₇/₂ dipole-forbidden transition. (FRE) Nous avons calculé les probabilités de transition radiative provenant des niveaux de Pb(II) ns ²S₁/₂, np ²P₁/₂,₃/₂, nd ²D₃/₂,₅/₂, nf ²F₅/₂,₇/₂, and 6p² (⁴P₁/₂,₃/₂,₅/₂, ²D₃/₂,₅/₂, ²P₁/₂,₃/₂, and ²S₁/₂). Les demi-vies sont évaluées à partir de ces probabilités. Les valeurs numériques ont été obtenues de deux façons, utilisant l’approche du couplage intermédiaire (I.C.) et un calcul Hartree–Fock relativiste complet. En I.C., nous utilisons l’approche habituelle d’ajustement moindre carré des niveaux à des valeurs expérimentales en utilisant le programme de Cowan. Les résultats des calculs sont comparés aux valeurs expérimentales trouvée dans la littérature scientifique ainsi qu’à d’autres valeurs théoriques. L’accord est généralement très bon entre nos résultats et les valeurs expérimentales. Une analyse des interactions montre que le niveau ⁴P₅/₂ de la configuration 6s6p² a une contribution importante du niveau ²D₅/₂ de la configuration 6s²6d. Ce résultat explique le bon accord entre nos résultats et les valeurs expérimentales pour la transition dipolaire interdite 6s6p² ⁴P₅/₂ – 6s²5f²F₇/₂.

We report here highly novel emission characteristics of naphthalylnaphthalene which are manifestations of the violation of the energy‐gap law in radiationless transitions.

On the basis of full relativistic theory, transition probabilities of 2p4f—2p3d for NⅡ have been calculated using multi-configuration Dirac-Fock method. The results are well consistent with experimental value. In the present work, the influence of relativistic effects, electron correlation, relaxation effects, Breit interaction and quantum electrodynamic effects on fine structure and transition probabilities are investigated in detail. The results show that the relativistic effects, electron correlation and relaxation effects are important to the calculations of energy structure and transition probabilities.

The saddle-point variational method is used with restricted variation method to obtain the energies of the core-excited states 1s2smd4De(m=3—7) and 1s2pnd4Do(n=3—5) for lithium, including the mass polarization and relativistic corrections. Oscillator strengths, transition rates, lifetimes and wavelengths are also calculated. The results are compared with other theoretical and experiment data in the literature.

The Rayleigh-Ritz variational method is used with a multiconfiguration-interaction function and restricted variation method to obtain the energies of 1s22s2 1S, 1s22s2p1P0, 1s22s2p3P0 and 1s22p2 3P in beryllium-like boron, including the mass polarization and relativistic corrections. Fine structure, oscillator strengths, transition rates and wavelengths are also calculated. The results are compared with other theoretical and experiment data in the literature.

Bond-selective chemistry, infrared multiphoton dissociation, relaxation time, absorption cross section, excitation rate, superradiance, spontaneous radiative transition, superabsorption