共查询到20条相似文献,搜索用时 15 毫秒
1.
L. Qu Z. Wang B. Li 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):173-177
The nonrelativistic dipole-length, -velocity and -acceleration absorption oscillator strengths for the 1s22s-1s2np (3 £ n £ 9)(3\leq n\leq 9) transitions of the lithium isoelectronic sequence up to Z=10 are calculated by using the energies and the multiconfiguration interaction wave functions obtained from a full core plus correlation (FCPC) method. In most cases, the agreement between the f-values from the length and velocity formulae is up to forth or fifth digit. Combining these discrete oscillator strengths with the single channel quantum defect theory (QDT), the discrete oscillator strengths for the transitions from the 1s22s state to highly excited levels (n 3 10n \geq 10) and the oscillator strength densities corresponding to the bound-free transitions are obtained. 相似文献
2.
E. Biemont 《Journal of Quantitative Spectroscopy & Radiative Transfer》1975,15(6):531-542
Hartree-Fock wavefunctions for 1s22s22p6nl (nl = 3,4,5s; 3,4,5p; 3,4,5d and 6f) configurations of the sodium isoelectronic sequence have been calculated up to Z = 26. Oscillator strengths for electric dipole transitions have been computed with the dipole length form of the transition matrix element. The study of systematic trends of these oscillator strengths along the isoelectronic sequence has allowed us to obtain new f-values and to improve some previous results. 相似文献
3.
M. A. Ali 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,20(6):565-567
Hartree-Fock energies of 1s2snd 4D, 1s2pnp 4D and 1s2pnd 4D0, n=3–5 of lithium isoelectronic sequence from Li to Ne+7 are reported. These results in conjunction with the energy of the lowest 4P and 4P0 states of the lithium isoelectronic sequence as calculated by Holoien and Geltman, are used to check some proposed assignments of lines obtained in beamfoil spectroscopy of Be(II), C(IV) and N(V). 相似文献
4.
应用屏蔽氢模型计算类钠等电子系列电偶极子跃迁振子强度f和原子(离子)实极化系数α,计算结果和有关文献是一致的;并讨论极化系数随主量子数、原子序数的变化情况. 相似文献
5.
Discrepancies between theoretical and experimental estimates of the oscillator strengths of the sodium isoelectronic sequence resonance transition are considered in the light of recent multi-configuration Hartree-Fock results. Possible experimental difficulties in the cascading analysis arising from a peculiar pattern of excited-state lifetimes are examined using computer simulations of decay curves. 相似文献
6.
The quantum defect orbital formalism in both its relativistic and non-relativistic versions has been applied to the calculation of oscillator strengths in the sharp spectral series of some boron-like systems. The results are presented in both tabular and graphical forms. 相似文献
7.
Line strengthsS for the dipole allowed transitions within then=2 complex of the oxygen isoelectronic sequence have been fitted in the formZ
2
S=A+B/(Z −C), whereZ is the nuclear charge of a particular ion. The constantsA, B andC are determined by using a non-linear least square method. The data forS are taken from the configuration interaction calculations which included internal, semi-internal and all external type correlations
for ions in the rangeZ=8 − 25. It is shown that the values ofA obtained from the fit for all the transitions are in excellent accord with the ab-initio values obtained in the hydrogenic
limitZ → ∞ provided near degeneracy effects are included in the ground state multiplet 1s22s22p4
1S. 相似文献
8.
Ronald F. Stewart 《Molecular physics》2013,111(5):1577-1583
For a wide range of frequencies the time-dependent Hartree-Fock equations are solved numerically for atoms of the Ne isoelectronic sequence. From the solutions properties of each system are calculated, notably excitation energies and bound-bound oscillator strengths. Excellent agreement is observed between the TDHF oscillator strengths and the most accurate experimental and theoretical data which are currently available. 相似文献
9.
D.K. Datta S.K. Ghoshal S. Sengupta 《Journal of Quantitative Spectroscopy & Radiative Transfer》1976,16(1):49-52
Oscillator strengths for 11S?n1P transitions for some members of the helium isoelectronic sequence have been calculated by utilizing the dipole length, velocity and acceleration forms of the transition matrix element with coupled H.F. wave functions. Good agreement has been obtained between the values of the oscillator strengths. The quantities and decrease slowly with nuclear charge Z, whereas first increase to a maximum value and then decreases slowly. 相似文献
10.
J. Migdalek W.E. Baylis 《Journal of Quantitative Spectroscopy & Radiative Transfer》1979,22(2):127-134
Relativistic single-configuration Hartree-Fock oscillator strengths for the lowest ns2S→ np2P, transitions in the first few members of the rubidium (n = 5) and cesium (n = 6) isoelectronic sequences have been studied, both with and without allowance for core polarization. The effect of polarization of the core of the atom or ion by the valence electron is included by introducing a polarization potential in the one-electron Hamiltonian and by employing the corresponding correction for the dipole-moment operator in the transition matrix element. The results obtained compare well with available experimental data and indicate a significant influence of core-polarization effects on oscillator strengths. The behaviour of the oscillator strengths for the low Z part of the isoelectronic sequences is discussed. 相似文献
11.
S. N. Tiwary 《International Journal of Theoretical Physics》1993,32(11):2047-2051
We report the general trend of the nonrelativistic Hartree-Fock relativistic Hartree-Fock, nonrelativistic configuration-interaction, and relativistic configuration-interaction length form of the oscillator strengths for the resonance excitation 1s
22s
22p63s
2
S
J
e
1s
22s
22p
53s
2
2
P
J
o
. transition, which leads to autoionization (Auger transition), in Na, Mg1+, Al2+, Si3+, P4+, S5+, Cl6+, Ar7+, K8+, Ca9+, Sc10+, Ti11+, Fe15+, Cu18+, Zn19+, Br24+, and Kr25+ ions of the sodium isoelectronic sequence. 相似文献
12.
Using the full relativistic quantum mechanics(GRASP2),we have calculated systematically the 3p2-3p1 and 3p1 -3p0 magnetic dipold m1 energy level scparations,transition probabilities and cscillator strengths in the 3s3p configuration of the magnesium seque 相似文献
13.
Line strengthS and radial matrix elementσ for the dipole allowed transitions withinn=2 complex of ions in the Be isoelectronic sequence have been fitted in the formsZ
2
S=A+B/(Z − C) andZσ=A′ + B′/(Z − C′). The constantsA, B, C andA′, B′, C′ have been calculated by employing a non-linear least square method. The relevant data forS andσ have been taken from calculations which includes correlation effects. It is shown that the fitted yalues ofA andA′ are in excellent accord with their hydrogenic values (Z →α) provided that we express the zeroth-order wavefunction of the ground state 1s22s2
1
S as a quantum-mechanical admixture of the Hartree-Fock (HF) state 1s22s2
1
S and the near-degenerate state 1s22p2
1
S. 相似文献
14.
R.P. McEachran M. Cohen 《Journal of Quantitative Spectroscopy & Radiative Transfer》1982,27(2):111-117
Orbital wave functions of a large number of ns-, np-, and nd-levels of the first five members of the boron isoelectronic sequence have been calculated using a frozen-core Hartree-Fock procedure augmented by an l-dependent core polarisation potential. The calculated ionisation energies are generally in very good agreement with observations. Electric dipole oscillator strenghts have been derived from the calculated orbitals and energies and have been used to yield simple interpolation formulae for f-values of higher members of the sequence. They are expected to be of high accuracy in many cases. 相似文献
15.
1INTRODUCTIONTheprecisioncalculationofthelithiumlikesystemswitha1s2corepresentaformidablechalenge[1].Forsomecoreexcitedlithiu... 相似文献
16.
J. Migdałek W.E. Baylis 《Journal of Quantitative Spectroscopy & Radiative Transfer》1979,22(2):113-125
Relativistic, single-configuration Hartree-Fock oscillator strengths for the lowest ns2S→np2P and np2P→nd2D transitions in the first few members of the silver (n = 5) and gold (n = 6) isoelectronic sequences have been studied, both with and without allowance for core polarization. Core polarization is included by introducing a polarization potential in the one-electron Hamiltonian and by employing the corresponding correction for the dipole-moment operator in the transition matrix element. The results obtained are compared with available experimental data and the influence of core-polarization effects on oscillator strengths is discussed. 相似文献
17.
利用全实加关联的方法计算类锂体系(Z=11~20) 1s24s -1s2np(5≤n≤9)的跃迁能, 将相对论效应(电子动能的相对论修正,Darwin项,电子-电子接触项以及轨道-轨道相互作用)和质量极化效应作为微扰,计算了它们对体系能量的修正.利用得到的波函数和跃迁能计算了核电荷Z=11~20的类锂离子的1s24s -1s2np(5≤n≤9)偶极跃迁的长度、速度和加速度三种规范下的振子强度,与现有的实验数据比较,结果符合得很好. 相似文献
18.
V. A. Zilitis 《Optics and Spectroscopy》2007,103(6):895-898
The oscillator strengths f of the resonance transitions are calculated by the Dirac-Fock method for the first ten terms of the rubidium isoelectronic sequence. The variation of f values along the isoelectronic sequence is analyzed. The corresponding transition probabilities and lifetimes τ of the levels 5p 2 P 1/2 and 5p 2 P 3/2 are calculated. The dependence of τ on the ion charge is approximated by an analytical equation. The obtained values of f and τ are compared with experiment and other calculations. 相似文献
19.
利用全实加关联的方法计算类锂体系(Z=11~20) 1s~24s -1s~2np(5≤n≤9)的跃迁能, 将相对论效应(电子动能的相对论修正,Darwin项,电子-电子接触项以及轨道-轨道相互作用)和质量极化效应作为微扰,计算了它们对体系能量的修正.利用得到的波函数和跃迁能计算了核电荷Z=11~20的类锂离子的1s~24s -1s~2np(5≤n≤9)偶极跃迁的长度、速度和加速度三种规范下的振子强度,与现有的实验数据比较,结果符合得很好. 相似文献
20.
V. A. Zilitis 《Optics and Spectroscopy》2014,116(4):513-515
A new method of data transmission in DWDM systems along existing long-distance fiber-optic communication lines is proposed. The existing method, e.g., uses 32 wavelengths in the NRZ code with an average power of 16 conventional units (16 units and 16 zeros on the average) and transmission of 32 bits/cycle. In the new method, one of 124 wavelengths with a duration of one cycle each (at any time instant, no more than 16 obligatory different wavelengths) and capacity of 4 bits with an average power of 15 conventional units and rate of 64 bits/cycle is transmitted at every instant of a 1/16 cycle. The cross modulation and double Rayleigh scattering are significantly decreased owing to uniform distribution of power over time at different wavelengths. The time redundancy (forward error correction (FEC)) is about 7% and allows one to achieve a coding enhancement of about 6 dB by detecting and removing deletions and errors simultaneously. 相似文献