共查询到20条相似文献,搜索用时 31 毫秒
1.
We compare coupled-cluster (CC) and configuration-interaction (CI) results for 55Ni and 57Ni obtained in the pf-shell basis, focusing on the practical equation-of-motion (EOM) CC approximations that can be applied to systems with dozens of correlated fermions. The weight of the reference state and the strength of correlation effects are controlled by the gap between the f7/2 orbit and the f5/2, p3/2, p1/2 orbits. Independent of the gap, the CC methods with up to 2p-2h components in the cluster operator and 3p-2h/3h-2p components in the EOMCC excitation operator are more accurate than the computationally more demanding CI approach with up to 3p-3h excitations and almost as accurate as the even more demanding CI approach truncated at 4p-4h excitations. 相似文献
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蔡灵仓 《光谱学与光谱分析》1998,18(3):273-278
本文对类镓等电子序列GaI-XeXXIV离子4s^24p、4s^24p、4s^24d、4s4p^2、4p^3和4s^25s组态组级结果和组态相互作用了理论分析,找出沿等电子序列的变化规律。 相似文献
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Gaudefroy L Sorlin O Beaumel D Blumenfeld Y Dombrádi Z Fortier S Franchoo S Gélin M Gibelin J Grévy S Hammache F Ibrahim F Kemper KW Kratz KL Lukyanov SM Monrozeau C Nalpas L Nowacki F Ostrowski AN Otsuka T Penionzhkevich YE Piekarewicz J Pollacco EC Roussel-Chomaz P Rich E Scarpaci JA St Laurent MG Sohler D Stanoiu M Suzuki T Tryggestad E Verney D 《Physical review letters》2006,97(9):092501
The N = 28 shell closure has been investigated via the 46Ar(d,p)47Ar transfer reaction in inverse kinematics. Energies and spectroscopic factors of the neutron p(3/2), p(1/2), and f(5/2) states in 47Ar were determined and compared to those of the 49Ca isotone. We deduced a reduction of the N = 28 gap by 330(90) keV and spin-orbit weakenings of approximately 10(2) and 45(10)% for the f and p states, respectively. Such large variations for the f and p spin-orbit splittings could be accounted for by the proton-neutron tensor force and by the density dependence of the spin-orbit interaction, respectively. This contrasts with the picture of the spin-orbit interaction as a surface term only. 相似文献
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A. Pfitzner 《Nuclear Physics A》1967,100(3):673-682
Balashov's resonance approximation is used to calculate the level shifts and widths of the low-lying, negative-parity states in 17O, assuming these states to be 2p-1h structure. It turns out that the coupling to one-particle continuum states is very important not only for the widths but also for the positions of most of the levels. The results prove to be very sensitive to the positions of the single-particle resonances in the (2p, 1f) shell. 相似文献
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Neyens G Kowalska M Yordanov D Blaum K Himpe P Lievens P Mallion S Neugart R Vermeulen N Utsuno Y Otsuka T 《Physical review letters》2005,94(2):022501
Unambiguous values of the spin and magnetic moment of 31Mg are obtained by combining the results of a hyperfine-structure measurement and a beta-NMR measurement, both performed with an optically polarized ion beam. With a measured nuclear g factor and spin I=1/2, the magnetic moment mu(31Mg)=-0.88355(15)mu(N) is deduced. A revised level scheme of 31Mg (Z=12, N=19) with ground state spin/parity I(pi)=1/2(+) is presented, revealing the coexistence of 1p-1h and 2p-2h intruder states below 500 keV. Advanced shell-model calculations and the Nilsson model suggest that the I(pi)=1/2(+) ground state is a strongly prolate deformed intruder state. This result plays a key role for the understanding of nuclear structure changes due to the disappearance of the N=20 shell gap in neutron-rich nuclei. 相似文献
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本文采用Hartree-Fock自洽场方法,从理论上计算了类锂氯离子和类锂钾离子可能实现软X射线激光的有关能级能量及跃迁谱线性质:跃迁波长、跃迁几率和振子强度。计算结果表明,类锂钾离子的部分跃迁非常有可能实现软X射线激光,并且其中有三条谱线的波长已进入水窗。 相似文献
8.
H. T. Fortune R. Middleton M. E. Cobern G. E. Moore S. Mordechai R. V. Kollarits 《Physics letters. [Part B]》1977,70(4):408-410
The 14C(t, p)16C reaction locates five new states in 16C, at excitation energies of 3120 ± 15, 3983 ± 10, 4136 ± 10 and 6109 ± 15 keV, in addition to the g.s. and 1.76 MeV states. The 3.02 and 3.98 MeV states appear to be the second 0+ and 2+ 2p-2h states, respectively. The 4.14 MeV state has Jπ = 4+ and the 6.11 MeV state has Jπ = 2+, 3−, or 4+. 相似文献
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L. D. Skouras 《Nuclear Physics A》1974,220(3):604-620
An extended model allowing for the mixing between 4p spherical and 6p-2h deformed configurations is introduced for the interpretation of the even parity spectrum of 44Ca. Six intrinsic 6p-2h configurations are considered in the calculation. The theoretical results are found to be in good agreement with experimental results, both on energy levels and transition rates. 相似文献
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Stripping and pickup reactions are performed and show the configuration for the lowest 3?state (7.62MeV) to be mainly a hole in the 1p shell the next 3?level (8.36 MeV) is mainly promoted into the 2p-1f shell. 相似文献
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We consider the shadow system of the Gierer-Meinhardt system in a smooth bounded domain Omega subset R(N),A(t)=epsilon(2)DeltaA-A+A(p)/xi(q),x is element of Omega, t>0, tau/Omega/xi(t)=-/Omega/xi+1/xi(s) integral(Omega)A(r)dx, t>0 with the Robin boundary condition epsilon partial differentialA/partial differentialnu+a(A)A=0, x is element of partial differentialOmega, where a(A)>0, the reaction rates (p,q,r,s) satisfy 1
0, r>0, s>or=0, 1 1 and tau sufficiently small the interior spike is stable. (ii) For N=1 if r=2 and 1 1 such that for a is element of (a(0),1) and mu=2q/(s+1)(p-1) is element of (1,mu(0)) the near-boundary spike solution is unstable. This instability is not present for the Neumann boundary condition but only arises for the Robin boundary condition. Furthermore, we show that the corresponding eigenvalue is of order O(1) as epsilon-->0. 相似文献
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基于密度泛函理论的第一性原理计算程序包VASP(Vienna ab-initio Simulation Package),采用投影缀加平面波(Projector augmented wave,PAW)方法和具有三维周期性边界条件的超原胞模型,对Pt在Ce4O8团簇上的吸附特性进行了研究,结果表明Pt在Ce4O8团簇上的吸附作用很强,其吸附能大于Pt在CeO2晶体表面的吸附能.所得吸附构型可分为三类:单键类,双键类和多键类.对其中最稳定吸附构型的电子结构分析表明:Pt的吸附诱导出了间隙态.该态距离费米能级很近,使Pt/Ce4O8团簇活性很强.Pt与Ce4O8团簇发生了部分电荷转移,从而使其中的一个Ce4+还原为Ce3+.这些结果有助于理解在纳米尺度范围内Pt与CeO2的协同作用. 相似文献
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基于密度泛函理论的第一性原理计算程序包VASP(Vienna ab-initio Simulation Package), 采用投影缀加平面波(Projector augmented wave, PAW)方法和具有三维周期性边界条件的超原胞模型, 对Pt在Ce4O8团簇上的吸附特性进行了研究. 结果表明Pt在Ce4O8团簇上的吸附作用很强,其吸附能大于Pt在CeO2晶体表面的吸附能. 所得吸附构型可分为三类:单键类, 双键类和多键类. 对其中最稳定吸附构型的电子结构分析表明:Pt的吸附诱导出了间隙态. 该态距离费米能级很近,使Pt/Ce4O8团簇活性很强. Pt与Ce4O8团簇发生了部分电荷转移, 从而使其中的一个Ce4+还原为Ce3+. 这些结果有助于理解在纳米尺度范围内Pt与CeO2的协同作用. 相似文献
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J.M. Irvine G.S. Mani V. Pucknell A. Watt R.R. Whitehead 《Physics letters. [Part B]》1973,44(1):16-18
The results of an extended shell model calculation in the space spanned by the orbital and the whole of the sd-shell for the nucleus 20Ne are presented. The positions of the (4p-0h), (6p-2h) and (8p-4h) bands are located and the results are compared with recent experiments. 相似文献
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用准相对论Hartree-Fock方法对Nb XIII离子二电子激发组态3d94s2, 3d94s4p, 3d94p2 的能级结构做了全面系统的理论计算研究.在对已有研究结果分析的基础上, 运用最小二乘方法对径向积分参数进行了优化计算, 得到了与这些组态有关的电偶极允许跃迁的谱线波长和跃迁概率.计算结果与最新的实验值做了对比分析, 表明本文计算结果是准确的. 研究发现, 波长40.92 nm的谱线, 属于3d94s(1D)4p2F7/2–3d9 (2D)4s2 2D5/2 的跃迁谱线, 而不属于3d94s (1D)4p4D7/2–3d9(2D)4s2 2D5/2 的跃迁谱线, 即上谱项能级为2F7/2, 而不是4D7/2.
关键词:
Nb XIII离子
二电子激发组态
谱线波长
跃迁概率 相似文献
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基于第一性原理的赝势平面波方法,对异质外延关系为Ru2Si3(100)//Si(001),取向关系为Ru2Si3[010]//Si[110]正交相的Ru2Si3平衡体系下能带结构、态密度和光学性质等进行了理论计算.计算结果表明:当1.087 nm≤a≤1.099 nm时,正交相Ru2Si3的带隙值随着晶格常数a取值的增大而增大.当a取值为1.093 nm时,体系处于稳定状态,此时Ru2Si3是具有带隙值为0.773 eV的直接带隙半导体.Ru2Si3价带主要是由Si的3p,3s态电子及Ru 4d态电子构成;导带主要由Ru的4d及Si的3p态电子构成.外延稳定态及其附近各点处Ru2Si3介电函数的实部和虚部变化趋势基本一致,但外延稳定态Ru2Si3介电函数的曲线相对往低能区漂移,出现的介电峰减少且峰的强度明显增强. 相似文献
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Wiedeking M Tabor SL Pavan J Volya A Aguilar AL Calderin IJ Campbell DB Cluff WT Diffenderfer E Fridmann J Hoffman CR Kemper KW Lee S Riley MA Roeder BT Teal C Tripathi V Wiedenhöver I 《Physical review letters》2005,94(13):132501
Excited states in 20O were populated in the reaction 10Be(14C,alpha) at Florida State University (FSU). Charged particles were detected with a particle telescope consisting of 4 annularly segmented Si surface barrier detectors and gamma radiation was detected with the FSU gamma detector array. Five new states were observed below 6 MeV from the alpha-gamma and alpha-gamma-gamma coincidence data. Shell model calculations suggest that most of the newly observed states are core-excited 1p-1h excitations across the N=Z=8 shell gap. Comparisons between experimental data and calculations for the neutron-rich O and F isotopes imply a steady reduction of the p-sd shell gap as neutrons are added. 相似文献
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Tripathi V Tabor SL Mantica PF Utsuno Y Bender P Cook J Hoffman CR Lee S Otsuka T Pereira J Perry M Pepper K Pinter JS Stoker J Volya A Weisshaar D 《Physical review letters》2008,101(14):142504
The beta decay of 33Mg (N=21) presented in this Letter reveals intruder configurations in both the parent and the daughter nucleus. The lowest excited states in the N=20 daughter nucleus, 33Al, are found to have nearly 2p-2h intruder configuration, thus extending the "island of inversion" beyond Mg. The allowed direct beta-decay branch to the 5/2{+} ground state of the daughter nucleus 33Al implies positive parity for the ground state of the parent 33Mg, contrary to an earlier suggestion of negative parity from a g-factor measurement. An admixture of 1p-1h and 3p-3h configurations is proposed for the ground state of 33Mg to explain all of the experimental observables. 相似文献
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《Nuclear Physics A》1986,458(1):12-24
The magnitude of the isospin mixing in the initial 1p-1h doorway state and in the underlying compound states of the 28Si giant dipole resonance is estimated from (γ, p), (γ, α) and (γ, n) cross sections. From the mixing coefficients, mixing widths of about 40 keV and 25 keV are deduced for the 1p-1h state and for the compound states respectively. This seems to indicate that the isospin mixing widths are roughly independent of the complexity and lifetime of the state involved. 相似文献