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1.
In this paper we present calculations of electron impact excitation collision strengths for transitions among the 89 fine-structure levels of the 2s22p6, 2s22p53, 2s2p63, 2s22p54, and 2s2p64 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   

2.
The R-matrix method is used to calculate the total photoionization cross-sections from the ground 2s 22p 6 1 S e and the first three excited 2s 22p 53p 3,1 S e states of Al IV, for photon energies ranging from the first ionization threshold to just above the second threshold of the residual ion Al V. The two lowest LS terms of Al V − 2s 22p 5 2 P 0, 2s2p 6 2 S e, 2s2p 6 2 S e, represented by sophisticated configuration interaction wavefunctions, are included in the R-matrix calculation. The resulting cross-sections are affected by Rydberg series of resonances converging to the 2s2p 6 2 S e excited threshold.  相似文献   

3.
In a recent paper, Verma et al. [Eur. Phys. J. D 42, 235 (2007)] have reported results for energy levels, radiative rates, collision strengths, and effective collision strengths for transitions among the lowest 17 levels of the (1s22s22p6)3s23p6, 3s23p53d and 3s3p63d configurations of Ni xi. They adopted the civ3 and R-matrix codes for the generation of wavefunctions and the scattering process, respectively. In this paper, through two independent calculations performed with the fully relativistic darc (along with grasp) and fac codes, we demonstrate that their results are unreliable. New data are presented and their accuracy is assessed.  相似文献   

4.
TheR-matrix method is used to calculate cross-sections for the photoionization of Ne-like Fe16+ from ground 2s 22p 61 S e and excited states belonging to 2s2p 6 3l and 2s 22p 5 3l configurations. Configuration interaction wavefunctions are used to represent two target states of Fe17+ ion retained in theR-matrix expansion. The cross-sections are obtained as a function of kinetic energy (ε k) of the ejected electron from 10 to 24 Ry. For low kinetic energy the cross-sections show series of Rydberg states which converge onto2 S e threshold Fe17+. The calculations are carried out in the LS coupling.  相似文献   

5.
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   

6.
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   

7.
孙长平  王国利  周效信 《物理学报》2011,60(5):53202-053202
利用R矩阵方法计算了F3+和Ne4+离子的基态2s22p2(3P)和激发态2s22p2 (1D,1S),2s2p3 (5So)的分波光电离截面、总光电离截面,分析辨认出了这些离子在自光电离过 关键词: 3+离子和Ne4+离子')" href="#">F3+离子和Ne4+离子 光电离 自电离共振 R矩阵')" href="#">R矩阵  相似文献   

8.
使用密度泛函理论下的第一性原理方法,对Wn原子团簇(n=3—27)的结构特性进行了理论计算. 得到了Wn团簇(n=3—7)的最低能量结构和(n=8—27)的局域能量极小的典型结构. 使用凝胶模型,提出的电子组态1s21p61d102s21f142p63s 关键词: W团簇 结构性质 稳定性 从头计算  相似文献   

9.
杨宁选  董晨钟  蒋军  颉录有 《中国物理 B》2010,19(9):93101-093101
This paper calculates the electron impact excitation rate coefficients from the ground term 2s22p2 3P to the excited terms of the 2s22p2, 2s2p3, 2s22p3s, 2s22p3p, and 2s22p3d configurations of N II. In the calculations, multiconfiguration Dirac--Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.  相似文献   

10.
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   

11.
In a recent paper (Tranet al, Ann. Phys.311, 204 (2004)), some asymptotic number theoretical results on the partitioning of an integer were derived exploiting its connection to the quantum density of states of a many-particle system. We generalise these results to obtain an asymptotic formula for therestricted or coloured partitionsp k s (n), which is the number of partitions of an integern into the summand of sth powers of integers such that each power of a given integer may occur utmostk times. While the method is not rigorous, it reproduces the well-known asymptotic results fors = 1 apart from yielding more general results for arbitrary values ofs.  相似文献   

12.
The close coupling R-matrix method is used to calculate cross-sections for photoionization of Mg III from its first three excited states. Configuration interaction wave functions are used to represent two target states of Mg III retained in the R-matrix expansion. The positions and effective quantum numbers for the Rydberg series converging to the excited state 2s 22p 6 2 S e of the residual ion, are predicted.  相似文献   

13.
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   

14.
We report on the calculations of transition wavelengths and weighted oscillator strengths for 2s22p6-2s2p6np (4 ≤ n ≤ 20) electric dipole (E1) transitions of Cu19+ ion. The flexible atomic code (FAC) has been adopted for the calculations. Comparisons are made with the experimental data available, showing that the present results for 4 ≤ n ≤ 6 are more accurate than the previous calculated values. Furthermore, combining the quantum defect theory (QDT) with the transition energies of 2s22p6-2s2p6np, the quantum defects for 2s2p6np Rydberg series of Cu19+ ion are determined. In addition, the energies of any highly excited states (n > 20) for this series can be reliably predicted using the QDT and the given quantum defects. The ionization energies for Cu19+ and Cu20+ ions are also calculated and they excellently accord with previous experimental and calculated values.  相似文献   

15.
Transitions between the five fine-structure levels in the 3s 23p 3 ground configuration of Fe XII (P-like) are of interest in astrophysics and terrestrial plasma diagnostics. The decay rates give rise to level lifetimes in the millisecond range, which have been measured recently at a heavy-ion storage ring. While most of the 3s 23p 23d levels are short-lived, two of these levels have no E1 decay channels and may also have millisecond lifetimes. We present HFR and MCDF calculations of the E1, M1, E2 and M2 transition rates between the 3s 23p 3, 3s3p4 and 3s 23p 23d levels and compare the lifetime results to most recent experimental data as well as to other predictions. Received 2 October 2001 / Received in final form 22 January 2002 Published online 28 June 2002  相似文献   

16.
The theory of the shapes of Auger decay lines of satellite two-hole-one particle states accompanying photoionization based on the Green's function method is developed. The lineshapes of Auger decay of satellite states [2 s 2 p ]( 1,3 P )3 s ( 2 P ), [2 s 2 p ]( 1 P )4 s ( 2 P ) and [3 s 3 p ]( 3 P )4 s ( 2 P ) in valence p-photoelectron spectra of Ne and Ar atoms are calculated (hole states are indicated by square brackets throughout). It is shown that in some cases the Auger lineshapes reproduce the shape of the photoelectron satellite line, but in other cases Auger line may be narrower then the photoelectron line and may have opposite direction of asymmetry. The theoretical results are in agreement with experimental low-energy Auger spectra. Received: 25 May 1998 / Accepted: 2 October 1998  相似文献   

17.
王宛珏 《物理学报》1992,41(5):726-731
本文用相对论多组态Dirac-Fock广义平均模型(MCDF-EAL)计算了可能成为激光工作物质的类氮KXIII,CaXIV,ScXV和TiXVI的2s2p3,2s2p4,2p5,2s2p23s,2s2p23p组态的各44条精细结构和24条3s—3p组态跃迁波长,其中关于KXIII,CaXIV,ScXV的3s,3p组态的计算值是本文预言的。  相似文献   

18.
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   

19.
The claim of Mohapatra and Maharana thattb(s) is a better scaling variable thant(lns)2 is put to test in the case of Λ-p scattering, after parametrizingb(s) asC 1 +C 2(lns)α. It was observed that in this case the data also prefer anα value which is close to those obtained by Mohapatra and Maharana for other scattering processes.  相似文献   

20.
Summary A detailed XPS study of the lithium-intercalated NiPS3 specimens was performed at the 2p, 3p, 3s core levels of the nickel atoms and at the 2p core levels of the sulphur and phosphorous atoms for various lithium contents. Comparison of the Ni 2p, 3p and 3s XPS spectra corresponding to NiPS3 and Li x NiPS3 systems shows some evident trends. In particular, a shift of the Ni main line towards lower binding energies, a decrease in the intensity of the Ni 3p, 2p satellite structures and a change in the full width at half maximum of the Ni 3s band with lithium content are observed. All these findings suggest a change in the 3d electron configuration for high lithium concentrations. As regards the cluster (P2S6)4−, with the addition of lithium, a P 2p main line shift towards higher binding energies is noted, while the S 2p peak shifts towards lower binding energies. These results are discussed in comparison with previous physical measurements concerning the nickel reduction process and the related electronic modifications. The authors of this paper have agreed to not receive the proofs for correction.  相似文献   

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