共查询到20条相似文献,搜索用时 187 毫秒
1.
We have calculated relativistic energies and Landé factors for 5d6s
2, 5d
26s, 6s6p
2, 6s
27s, 5d
3, 5d6s7s, 6s
26p, 5d6s6p, 5d
26p and 6s
27p excited levels outside the core [Xe]4f
14 in neutral lutetium (Lu I, Z = 71). These calculations are based on the multiconfiguration Hartree-Fock (MCHF) method, within the framework of the Breit-Pauli
relativistic corrections. Moreover, the results obtained have been compared with other works. 相似文献
2.
The adiabatic potential energy, the spectroscopic constants and the transition dipole moments of the lowest electronic states of the LiK+ molecule, dissociating into Li(2s, 2p, 3s, 3p, 3d, 4s, and 4p) + K+ and Li+ + K(4s, 4p, 5s, 3d, 5p, 4d, and 6s), have been investigated. We have used an ab initio approach involving a non-empirical pseudopotential for the Li (1s2) and K (1s22s22p63s23p6) cores and core valence correlation correction. A very good agreement has been obtained for the ground state for the spectroscopic constants with the available theoretical works. The transition dipole moment from X2Σ, 22Σ, 32Σ, and 42Σ states to higher excited states have been determined. Numerous avoided crossing between electronic states of 2Σ and 2Π symmetries, have been localised and analysed. Their existences are related to the charge transfer process between the two ionic systems Li+K and LiK+. 相似文献
3.
P. Grundevik H. Lundberg L. Nilsson G. Olsson 《Zeitschrift für Physik A Hadrons and Nuclei》1982,306(3):195-209
High-resolution laser fluorescence spectroscopy, using a single-mode dye laser acting on a collimated atomic beam, has been performed to determine the hyperfine-structure (hfs) constants in six states of the 6p 5d configuration of135Ba and137Ba. Isotope shifts (IS) for eleven transitions between the 6s 5d and the 6p 5d configurations have also been measured. From an analysis of the energy levels, intermediate angular wavefunctions have been deduced. The wavefunctions are used to evaluate experimental hyperfine parameters from the experimental hfs constants. The parameters are, for the magnetic-dipole interaction compared with theoretical values, and for the electricquadrupole interaction used to estimate the nuclear quadrupole moments for the odd isotopes. The IS in the measured transitions are analysed using a King-plot, with the first resonance line in Ba II as the reference. Specific mass and field shifts are evaluated for the measured transitions. The field shifts have been used to determine the change in mean-square radius between the natural abundant Ba-isotopes. 相似文献
4.
A. N. Ryabtsev E. Ya. Kononov R. R. Kildiyarova W. -ü. L. Tchang-Brillet J. -F. Wyart 《Optics and Spectroscopy》2012,113(2):109-114
Spectra of hafnium, tantalum, tungsten, and rhenium in the range of 145?C350?, excited in a low-inductive vacuum spark, have been recorded on a grazing-incidence vacuum spectrograph using a grating with 3600 lines/mm and a radius of 3 m. The wavelengths and intensities of more than 3800 lines in the tungsten spectrum have been measured. Comparison with the Hartree-Fock calculations showed that most spectral lines should be due to transitions in the W VIII spectrum. Short-wavelength lines due to the 4f 135s 25p 6-4f 135s 25p 56s transitions have been identified in the W VIII spectrum and the Re IX, Ta VII, and Hf VI isoelectronic spectra. 相似文献
5.
A mechanism of the laser action of 5d
8 6s
2 –5d
9 6p HgIII transitions is proposed. The explanation is based on atomic constants of the transitions and the predominant role of direct electron excitation of the upper laser level. The kinetic models of electron beam and hollow cathode discharge sources are calculated. The theoretical estimations are compared with experimental data and possible laser transitions are also proposed. The role of electron impact excitation in the formation of inverse population for two-electron transitions in CuII and AgII obtained in hollow cathode discharges is discussed. 相似文献
6.
W. Gaied H. Habli B. Oujia F. X. Gadea 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(3):371-378
The adiabatic potential energy curves of the low-lying electronic states of the MgAr
molecule dissociating into Mg (3s, 3p,
4s, 3d, 4p, 5s,
4d, 5p)+Ar have been investigated. The electronic
structure of the Mg-Ar molecule is calculated using [Mg2+] and [Ar] core
pseudopotentials complemented by the core polarization operators for both atoms,
considering the molecule to be a two-electron system. The derived spectroscopic constants
of the ground state and lower excited states are in good agreement with available
experimental and theoretical work. In addition, for the purpose of checking the
pseudopotential accuracy on a simpler related system, low lying potential energy curves of
the single active electron Mg+Ar ion are also reported and the corresponding
molecular constants are compared with those in the existing literature. 相似文献
7.
P. Grundevik M. Gustavsson G. Olsson T. Olsson 《Zeitschrift für Physik A Hadrons and Nuclei》1983,312(1-2):1-9
Measurements of the hyperfine structures in the 6p5d 1 D 2,3 D 1 and3 F 2, 3, 4 states of135Ba and137Ba, and isotope-shifts in several far-red transitions between the 6s 5d and 6p 5d configurations, as well as the transition 6s 2 1 S 0→6s6p 3 P 1 at 7,911 Å have been performed using high-resolution laser spectroscopy on a collimated atomic beam of natural barium. An analysis of the magnetic-dipole interaction in the 6p 5d configuration using effective one- and two-body hyperfine operators is presented. In particular the contact interaction was studied with respect to the correlation between the two valence electrons. Effects of strong configuration interaction were found. From a King-plot analysis of the isotope shift term- andJ-dependence of the field shift have been evaluated for the transitions between the 6s 5d and 6p 5d configurations. Relativistic Hartree-Fock (RHF) calculations have been performed of electron densities at the nucleus for six different configurations in Ba I and Ba II. The RHF calculations reproduce the experimental King-plot slopes quite well, while the absolute values, of the changes in electron density at the nucleus for the studied transitions, are found to be 9% lower than the results derived from a muonic experiment. 相似文献
8.
A. V. Loginov 《Optics and Spectroscopy》2017,122(3):345-351
The probabilities of radiative electric dipole transitions 2p 53p, 2p 6–2p 53s, and 2p 53d in the spectrum of neon-like copper Cu XX and 5p 56p, 5p 6–5p 56s, 5p 57s, and 5p 55d in the spectrum of xenon-like lanthanum La IV are calculated. The wave functions of the intermediate coupling were found from the wellknown experimental energy levels by the least-squares method (LSM). To transfer to an absolute scale the radial integrals for the transitions calculated in the form of a length on the Hartree–Fock functions have been used. By summing the calculated probabilities of the transitions, the lifetimes of the levels of configurations 2p 53s, 2p 53p, and 2p 53d in the spectrum of Cu XX and levels of configurations 5p 56s, 5p 56p, and 5p 57s in the spectrum of La IV have been obtained. 相似文献
9.
In this paper we present calculations of electron impact excitation collision strengths for transitions among the 89 fine-structure
levels of the 2s22p6, 2s22p53ℓ, 2s2p63ℓ, 2s22p54ℓ, and 2s2p64ℓ configurations of Ni XIX, for which flexible atomic code (FAC) has been adopted. Comparisons are made with the earlier available
results in the literature, and the anomalies observed have been discussed.
相似文献
10.
G. P. Gupta A. Z. Msezane 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(2):157-160
Excitation energies from ground state for 97 fine-structure levels as well as oscillator strengths and radiative decay rates
for all electric-dipole-allowed and intercombination transitions among the fine-structure levels of the terms belonging to
the (1s
22s
22p
6)3s
23p, 3s
3
p
2, 3s
23d, 3p
3, 3s3p3d, 3p
23d, 3s3d
2, 3s
24s, 3s
24p, 3s
24d, 3s
24f, and 3s3p4s configurations of Co XV are calculated, using extensive configuration-interaction (CI) wave functions, obtained with the
CIV3 computer code of Hibbert. The important relativistic effects in intermediate coupling are included through the Breit-Pauli
approximation via spin-orbit, spin-other-orbit, spin-spin, Darwin and mass correction terms. Small adjustments to the diagonal
elements of the Hamiltonian matrices have been made. Our calculated excitation energies, including their ordering, are in
excellent agreement with the experimental results and the experimentally compiled energy values of the National Institute
for Standards and Technology (NIST) wherever available. The mixing among several fine-structure levels is found to be very
strong, with most of the strongly mixed levels belonging to the (1s
22s
22p
6)3p
23d and 3s3d
2 configurations. The strong mixing among several fine-structure levels makes it very difficult to identify them uniquely.
Perhaps, that may be the reason for the lack of both experimental and theoretical results for these levels. We believe that
our extensive calculated values can guide experimentalists in identifying the fine-structure levels in their future work.
From our radiative decay rates we have also calculated radiative lifetimes of some fine-structure levels. In this calculation
we also predict new data for several fine-structure levels where no other theoretical and/or experimental results are available. 相似文献
11.
S. Kröger A. Bouzed 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):63-72
A parametric analysis of the fine and the hyperfine structure for the three even configurations 4d45s, 4d
45s
2 and 4d5 has been performed. Effective one-electron parameters a
nl
kskl(k
s
k
l = 01, 12 and 10) and b
nl
02 were determined for these three configurations. Extremely large ratios a
4d
10/a
4d
01 were found. Theoretical predictions for the hyperfine structure constants A and B for all levels of the configurations 4d45s, 4d
45s
2 and 4d5 have been determined from experimental data. Additionally, the fine and hyperfine structure for the two energetically high
lying even configurations 4d46s and 4d35s6s are discussed. The results presented here call into doubt the existence of the fine structure levels 4d
35s6s
6
F
11/2 at an energy of 39 408.88 cm-1 and 4d
35s5p
6
G
13/2 at 18 876.46 cm-1 given in the Moore tables. 相似文献
12.
The multiconfiguration Hartree-Fock (MCHF) method is used to calculate the excitation energies and oscillator strengths, of
both the length (f
L) and velocity (f
V) forms, for 1s22s22p63s23p63d2
D→1s22s22p63s23p53d2
2
P
0,2
D
0,2
F
0 transitions in Cr5+, Mn6+ and Fe7+ ions of the potassium isoelectronic sequence. Comparison is made with our earlier relevant results obtained by employing
the configuration interaction (CI) method which is closely related to the MCHF method. Our present investigation demonstrates
that the MCHF method is more accurate than the CI method in all ions of present consideration. 相似文献
13.
M. A. Khodorkovskii S. V. Murashov T. O. Artamonova A. A. Belyaeva L. P. Rakcheeva A. A. Pastor P. Yu. Serdobintsev N. A. Timofeev I. A. Shevkunov I. A. Dement’ev R. Hallin J. Nordgren 《Optics and Spectroscopy》2010,108(6):899-914
The electronic spectra of XeNe molecules in the range of 77100-90100 cm-1 are measured by the method of laser resonance multiphoton ionization in a supersonic jet. The photoionization spectra are obtained upon two- and three-photon excitations of molecules and their ionization by the next photon. In the range of 80300-90100 cm-1 near Xe*(5d, 6p’, 6d, 7s, and 7p), the spectra are obtained for the first time. A whole number of vibrational systems are measured in this range. The majority of vibrational systems near Xe* (5d, 6d, 7p, and 7s) are located in the red range with respect to their dissociation limits. In the blue range with respect to the dissociation limits, continua corresponding to transitions of molecules from the ground state to repulsive potential curves of excited states are detected. For a number of excited states of XeNe molecules, the vibrational analysis is performed and molecular constants are estimated. 相似文献
14.
R. -H. Rinkleff 《Zeitschrift für Physik A Hadrons and Nuclei》1978,288(3):233-239
The level-crossing technique with parallel electric and magnetic fields was used to measure the tensor polarizabilities of six levels of the configuration 4f 13 6s6p + 4f 12 5d6s 2 in the Tm I-spectrum. Using intermediate coupling wave functions given by Camus and the experimental values of the tensor polarizabilities, the radial integrals for electric dipole transitions from levels of the configuration 4f 136s6p + 4f 125d6s 2 to levels of the configuration 4f 13 5d6s + 4f 12 6s 26p have been determined. The results areI(4f 136s6p,4f 135d6s)=1.98(45)ea 0 andI(4f 125d6s 2,4f 126s 26p) = 0.88(25)ea 0. A comparison between the experimental and the calculated values of the tensor polarizabilities shows an excellent agreement, provided that these radial integrals and the radial integrals for the electric dipole transitions to the ground state configuration 4f 136s 2 as determined by Wallenstein from lifetime measurements are used in the calculation, instead of radial integrals computed by Camus with Hartree-Fock wave functions. 相似文献
15.
H.L. Xu A. Persson S. Svanberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):233-236
New radiative lifetime measurements based on time-resolved laser-induced fluorescence techniques are reported for 18 even-parity
levels belonging to the 4f5d26p and 4f
25d
2 configurations of Ce I and 6 even-parity levels belonging to the 5d26s, 4f5d6p, and 4f6s6p configurations of Ce II. Free neutral and singly ionized cerium atoms were produced by laser ablation. The Ce I and Ce II
levels range in energy from 26 545 to 29 102 cm-1, and 42 573 to 48 152 cm-1, respectively.
Received 25 September 2002 Published online 4 March 2003 相似文献
16.
We have calculated the excitation energies, oscillator strengths and transition probabilities for electric-dipole-allowed
and intercombination transitions among the 46 LS levels belonging to the configurations 3s
23p
2, 3s3p
3, 3s
23p3d, 3p
4, 3s
23p4s, 3s
23p4p, 3s3p
2(2
S)4s, 3s3p
2(2
P)4s, 3s3p
2(4
P)4s, 3s3p
2(2
D)4s, 3s
23p4d and 3s
23p4f of Si-like Argon. These states are represented by extensive Configuration-Interaction (CI) wavefunctions obtained using the
CIV3 computer code of Hibbert. From our transition probabilities we have also calculated the radiative lifetimes of singlet
and triplet states of Ar V. Our results are compared with other available theoretical calculations and experimental data.
To assess the importance of relativistic effects on our calculated values, we have also carried out calculations in the intermediate-coupling
scheme using the Breit-Pauli Hamiltonian. Small adjustments to the diagonal elements of the Hamiltonian matrices have been
made so that the energy splittings are as close as possible to the experimentally compiled energy values of the National Institute
for standards and Technology (NIST). The energy splitting of 85 fine-structure levels, the oscillator strengths and transition
probabilities for electric-dipole-allowed and intercombination transitions and the lifetimes of some fine-structure levels
are presented and compared with available experimental and other theoretical values. In this calculation, we also predict
new data for several fine-structure levels where no other theoretical and experimental results are available. 相似文献
17.
E. Siefart 《Annalen der Physik》1977,489(4):286-294
Wave functions for the 3d 4s 4p, 3d2 4p and 4s2 4p configurations of ScI are calculated, taking into account departures from SL-coupling and configuration interaction and on fitting the radial integrals to the experimental fine structure energies. Using these wave functions g J -values are derived. The intermediate coupled hfs matrix elements of the 3d 4s 4p configuration are reduced to the unknown electron coupling constants as, ap and ad and calculated on estimating these constants from the spin-orbit coupling constants and fitting them to some experimental A-values. By this way the absolute phases of the experimental A((1P)2D)- and A((1P)2F)-values are obtained. Good agreement between calculated and most experimental data has been achieved. 相似文献
18.
利用基于全相对论框架下的多组态Dirac-Fock理论方法发展起来的程序包GRASP92和新发展的处理辐射跃迁过程的程序REOS99,计算了类镍等电子系列离子(Z=45—95)的基组态3s23p63d101S0以及低激发组态3s23p63d94l,3s23p53d104l和3s3p63d104l(l=s,p,d,f)的能级及其向基态的M1,M2,E2禁戒跃迁概率.通过分析高离化类镍离子在特定的原子序数范围内由于存在能级交叉而产生的强组态相互作用,解释了高离化类镍离子禁戒跃迁概率的反常变化现象,探讨了禁戒跃迁概率受强组态相互作用影响而变化的一般规律. 相似文献
19.
We have calculated relativistic energies, Landé factors and lifetimes for 5d6s
2, 5d
26s, 6s
2
ns (n = 7–14), 6s
2
nd (n = 6–25), 6s
2
ng (n = 5–7), 6s
2
np (n = 6–25), 5d6s6p and 6s
2
nf (n = 5–23) excited levels outside the core [Xe]4f14 in neutral lutetium (Z = 71) using Cowan’s relativistic Hartree-Fock (HFR) method. The results obtained have been compared
with other calculations and experiments. 相似文献
20.
Integral yields of spontaneous emission at wavelengths of 1.73, 2.03, and 2.65 μm have been measured upon excitation of pure xenon by a pulsed electron beam. These yields have been analyzed and experimental data have been obtained on time constants of radiative transitions 5d[3/2]1 → 6p[5/2]2, 5d[3/2]1 → 6p[3/2]1, and 5d[3/2]1 → 6p[1/2]0 of XeI, which appeared to be equal to (2300 ± 400) × 10?9, (300 ± 40) × 10?9, and (1300 ± 200) × 10?9 s, respectively. It is shown that the experimental data are in a qualitative agreement with the results of computational and theoretical investigations. The results of averaging the experimental and calculated data are proposed for use as recommended values of the corresponding constants. 相似文献