Oscillator strengths for 22S--n2P transitions of the lithium isoelectronic sequence from Z = 11 to 20

The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s22s-1s2np (3≤n≤9) transitions of lithium-like systems from Z=11 to 20 are calculated by using the energies and the multiconfiguration interaction wave functions obtained from a full core plus correlation method, in which relativistic and mass-polarization effects on the energy, as the first-order perturbation corrections, are included. The results of three forms are in good agreement with each other, and closely agree with the experimental data available in the literature. Based on the quantum defects obtained with quantum defect theory (QDT), the discrete oscillator strengths for the transitions from the ground state to highly excited states 1s2np (n≥10) and oscillator strength densities corresponding to the bound-free transitions are obtained for these ions.     

Behaviours of the excited states 1s^2np along lithium isoelectronic sequence from Z=11 to 20

Based on the obtained energy values of 1s^2np （n≤ 9） states for lithium-like systems from Z=11 to 20 （by the authors of this paper： Hu M H and Wang Z W 2004 Chin. Phys. 13 662）, this paper determines the quantum defects, as slowly varying function of energy, of this Rydberg series. Using them as input, it can predict the energies of any highly excited states below the ionization threshold for this series a~cording to the quantum defect theory. The regularities of variation for quantum defects of the series along this isoelectronic sequence are physically analysed and discussed. The screening parameters, which are equal to the effective screening charge of the core-electrons, are also obtained.     

Wavefunction and energy of the 1s22sns configuration in a beryllium atom

A new set of trial functions for 1s^22sns configurations in a beryllium atom is suggested. A Mathematica program based on the variational method is developed to calculate the wavefunctions and energies of 1s^22sns （n = 3 - 6） configurations in a beryllium atom. Non-relativistic energy, polarization correction and relativistic correction which include mass correction, one- and two-body Darwin corrections, spin-spin contact interaction and orbit-orbit interaction, are calculated respectively. The results are in good agreement with experimental data.     

Cr~(21+)离子1s~23d-1s~2nf的跃迁能和偶极振子强度(英文)

用全实加关联方法计算了类锂Cr21+离子1s23d-1s2nf(4≤n≤9)的跃迁能和1s2nf(n≤9)态的精细结构.在类氢近似下估算了对能量的高阶相对论修正.依据量子亏损理论,确定了Rydberg系列1s2nf的量子数亏损.据此可以实现对任意高激发态(n≥10)的能量的可靠预言.计算了Cr21+离子1s23d-1s2nf(4≤n≤9)跃迁的振子强度.与量子亏损理论相结合,得到该离子从1s23d态到电离阈附近高激发束缚态间的偶极跃迁振子强度以及到相应连续态跃迁的振子强度密度,从而将Cr21+离子的这一重     

Theoretical study on behaviors of 1s22s-1s2np transition for Co24+ ion in the whole energy region

Non-relativistic energies of 1s²2s and 1s² np (n⩽9) states for Co²⁴⁺ ion are calculated by using the full-core plus correlation method. Our results of 1s²2s and 1s²2p states agree well with the high-precision results of Yan et al. Based on calculating the first-order corrections to the energy from relativistic and mass-polarization effects, we estimate the higher-order relativistic contribution and QED correction to the energy under a hydrogenic approximation. The transition energies, wavelengths and oscillator strengths for the 1s²2s−1s² np (n⩽9) transitions of this ion are calculated. The results agree with the experimental data available in literature satisfactorily. By combining with quantum defect theory, our theoretical predictions on the energy and oscillator strength of this ion are extrapolated to the whole energy region including continuous states.     

Mn22+离子1s22s-1s2np的偶极跃迁能和振子强度

用全实加关联方法计算了类锂Mn22 离子1s22s-1s2np(2≤n≤9)的偶极跃迁能和振子强度.1s2np(2≤n≤9)态的精细结构通过计算自旋-轨道与自旋-其他轨道相互作用算符的期待值确定.依据单通道量子亏损理论,确定了Rydberg系列1s2np的量子数亏损.从而可以用这些作为能量的缓变函数的量子亏损,实现对任意高激发态(n≥10)的能量的可靠预言.将这些分立态振子强度与单通道量子亏损理论相结合,得到在电离阈附近束缚态-束缚态跃迁振子强度以及束缚态-连续态跃迁的振子强度密度,从而将Mn22 离子的这一重要光谱特性的理论预言外推到整个能域.     

Oscillator strengths for 2 ^2P-n ^2D transitions of lithium-like systems with Z=11 to 20

The dipole-length, velocity and acceleration absorption oscillator strengths for the 1s^22p－1s^2nd(3≤n≤9) transitions of the lithium-like systems with Z=11 to 20 are calculated using the energies and the multiconfiguration interaction wavefunctions obtained from a full core plus correlation method. The agreement between the f-values calculated from the length, velocity and acceleration formulae is excellent. Our results agree closely with the experimental data available in the literature. Combining these discrete oscillator strengths with the single-channel quantum defect theory, the discrete oscillator strengths for the transitions from 1s^22p state to highly excited states (n≥10) and the oscillator strength densities corresponding to the bound-free transitions are obtained.     

Transition parameters of Li-like ions(Z = 7–11) in dense plasmas

The energy levels, transition energies, transition probabilities, weighted oscillator strengths, and line strengths of Lilike ions(Z = 7–11) in dense plasmas are investigated in this work. The relativistic effects and electron correlation effects are described by the MCDHF method. The ion sphere model is applied to include the dense plasma screening effect. The ground configuration 1 s~22 s and the excited 1 s~22 p, 1 s~23 l(l = 0–2) are considered. The configuration sets are enlarged until n = 7 where the calculated energy levels have converged. The critical free electron densities of 1 s~23 d states are estimated.Except for 1 s~23 s–1 s~23 p transitions, the transition energies for Δn = 0 increase, and for Δn ≠ 0 decrease with increasing free electron densities. For 1 s~23 s–1 s~23 p transitions, the spectra show blue-shift at lower free electron densities and red-shift at higher free electron densities, and the energy level crossing phenomens are observed at higher free electron densities.     

Sc+18离子的跃迁能和振子强度

用全实加关联方法计算了Sc⁺¹⁸离子1s²2s--1s²np (2≤n≤9) 和1s²2p--1s²nd (3≤n ≤9)的跃迁能和振子强度。1s²np和1s²nd 态的精细结构劈裂通过计算自旋-轨道及自旋-其他轨道相互作用算符的期待值加以确定。还得到了这两个里德堡系列的量子亏损（作为能量的函数）。依据三种规范的振子强度公式得到的计算结果相当好的一致。将这些计算结果与量子亏损理论相结合，进一步得到电离阈附近的分立态-分立态跃迁的振子强度和分立态-连续态跃迁的振子强度密度。     

V+20离子的能量和偶极振子强度

用全实加关联方法计算了类锂V+20离子 1s2nl(l=s,p, d;n≤9) 态的电离势和精细结构.依据单通道量子亏损理论, 确定了这三个Rydberg系列的量子数亏损.用这些作为能量的缓变函数的量子亏损,可以实现对任意高激发态(n≥10)的能量的可靠预言.用在计算能量过程中确定的波函数,计算了V+20离子1s22s-1s2np及1s22p-1s2nd (n≤9)跃迁的振子强度.将这些分立态振子强度与单通道量子亏损理论相结合,得到在电离域附近束缚态间的偶极跃迁振子强度以及束缚态-连续态跃迁的振子强度密度,从而将V+20离子的这一重要光谱特性的理论预言外推到整个能域.     

Optical parameters and energy levels splitting of Ho^3＋ in Ho^3＋： GdVO4

Ho^3＋ ： GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3＋ in the sample Ho^3＋： GdVO4. The intensity parameters are calculated by using the Judd-Ofelt theory. Some predicted spectroscopic parameters, such as the spontaneous radiative transition rate, branching ratio and integrated emission cross section are dealt with. And we also compare the optical parameters with those of other materials. From these results, it is found that there are many transitions which have large oscillator strengths and large integrated emission cross sections. Especially the transitions such as ^5 F4 → ^5 I 8, ^5 S2→^5 I8, ^5 F5 → ^5 I8 and ^5 I7 →^ 5 I8 are useful in solid-state lasers and other fields. Finally, we discuss the splitting of the energy levels of Ho^3＋ in the crystal GdVO4 based on the group theory.     

Structures and electronic properties of AUn-1Cu and AUn （n ≤ 9） clusters

A systematic study on the structure and electronic properties of gold clusters doped each with one copper atom has been performed using the density functional theory. The average bond lengths in the Aun-1Cu （n ≤ 9） bimetallic clusters are shorter than those in the corresponding pure gold clusters. The ionization potentials of the bimetallic clusters Aun-1Cu （n 〈 9） are larger than those of the corresponding homoatomic gold clusters except for Aus. The energy gaps of the Au-Cu binary clusters are narrower than those of the Aun clusters except AuCu and Au3Cu. No obvious even-odd effect exists in the variations of the electron affinities and ionization potentials for the Aun-1Cu （n ≤ 9） clusters, which is in contrast to the case of gold clusters Aun.     

Transition energy and dipole oscillator strength of 1s23d-1s2 nf transitions for Sc18+ ion

The transition energies of the 1s²3d-1s² nf (4?n?9) transitions and fine structure splittings of 1s² nf (n?9) states for Sc¹⁸⁺ ion are calculated with the full-core plus correlation method. The quantum defect of 1s² nf series is determined by the single-channel quantum defect theory. The energies of any highly excited states with n?10 for this series can be reliably predicted using the quantum defect as function of energy. Three alternative forms of the dipole oscillator strengths for the 1s²3d-1s² nf (n?9) transitions of Sc¹⁸⁺ ion are calculated with the transition energies and wave functions obtained above. Combining the quantum defect theory with the discrete oscillator strengths, the discrete oscillator strengths for 1s²3d-1s² nf (n > 9) transitions and the oscillator strengths densities corresponding to the bound-free transitions are obtained.     

Sc+18离子1s23d-1s2nf的跃迁能和偶极振子强度

用全实加关联方法计算了类锂Sc 18离子1s23d-1s2nf(4≤n≤9)的跃迁能和1s2nf(n≤9)态的精细结构。依据量子亏损理论确定了该Rydberg系列的量子数亏损,用这些作为能量的缓变函数的量子亏损,可以实现对任意高激发态(n≥10)的能量可靠的预言。利用在计算能量过程中确定的波函数,计算了Sc 18离子1s23d-1s2nf的偶极跃迁在三种规范下振子强度;将这些分立态振子强度与量子亏损理论相结合,得到在电离阈附近束缚态-束缚态跃迁振子强度以及束缚态-连续态跃迁振子强度密度,从而将Sc 18离子的这一重要光谱特性的理论预言外推到整个能域。     

Transition energy and dipole oscillator strength of 1s23d- 1s2nf transitions for Sc18+ ion

The transition energies of the 1s²3d-1s² nf (4⩽n⩽9) transitions and fine structure splittings of 1s² nf (n⩽9) states for Sc¹⁸⁺ ion are calculated with the full-core plus correlation method. The quantum defect of 1s² nf series is determined by the single-channel quantum defect theory. The energies of any highly excited states with n⩾10 for this series can be reliably predicted using the quantum defect as function of energy. Three alternative forms of the dipole oscillator strengths for the 1s²3d-1s² nf (n⩽9) transitions of Sc¹⁸⁺ ion are calculated with the transition energies and wave functions obtained above. Combining the quantum defect theory with the discrete oscillator strengths, the discrete oscillator strengths for 1s²3d-1s² nf (n > 9) transitions and the oscillator strengths densities corresponding to the bound-free transitions are obtained. __________ Translated from Chinese Journal of Atomic and Molecular Physics, 2005, 22(4) (in Chinese)     

A novel yellow emitting phosphor Dy3+, Bi3+ co-doped YVO4 potentially for white light emitting diodes

Novel Y1 x yVO4:xDy3+,yBi3+(0.01 ≤ x ≤ 0.05,0 ≤ y ≤ 0.20) phosphors for light emitting diode(LED) were successfully synthesised by solid-state reaction.The calculation results of electronic structure show that YVO4 has a direct band gap with 3 eV at G.The top of the valence band is dominated by O 2p state and the bottom of the conduction band is mainly composed of O 2p and V 3d states.An efficient yellow emission under near-ultraviolet(365 nm) excitation is observed.Compared with the pure YVO4:Dy3+ samples,the Dy3+,Bi3+ co-doped samples show a more intensive emission peak(at 574 nm) and a new broad emission band(450-770 nm),due to the 4F9/2 6H13/2 transition of Dy3+ and the emission of the VO3 4 Bi3+ complex respectively.The optimum chromaticity index of Y1 x yVO4:xDy3+,yBi3+(0.01 ≤ x ≤ 0.05,0 ≤ y ≤ 0.20) is(0.447,0.497),which indicates that YVO4:Dy3+,Bi3+ has higher colour saturation than the commercial phosphor YAG:Ce3+.The effects of concentration of Dy3+,Bi3+,electric states and the photoluminescence properties are discussed in details.     

Mn22+离子1s23d1s2nf的跃迁能和振子强度

用全实加关联方法计算了类锂Mn22 离子1s23d-1s2nf(4≤n≤9)的跃迁能和1s2nf(n≤9)态的精细结构,在类氢近似下估算了对能量的高阶相对论修正.依据量子亏损理论,确定了Rydberg系列1s2nf的量子数亏损,据此可以实现对任意高激发态(n≥10)的能量的可靠预言.计算了Mn22 离子1s23d-1s2nf(4≤n≤9)偶极跃迁的振子强度.     

Mutual recombination in slow Si^＋ ＋ H^- collisions

This paper studies the process of mutual neutralization of Si^＋ and H^- ions in slow collisions within the multichannel Landau-Zener model. All important ionic-covalent couplings in this collision system are included in the collision dynamics. The cross sections for population of specific final states of product Si atom are calculated in the CM energy range 0.05 e∨/u-5 ke∨/u. Both singlet and triplet states are considered. At collision energies below -10 e∨/u, the most populated singlet state is Si（3p4p, ^1S0）, while for energies above -150e∨/u it is the Si（3p, 4p, ^1P1） state. In the case of triplet states, the mixed 3p4p（^3S1 ＋^3P0） states are the most populated in the entire collision energy range investigated. The total cross section exhibits a broad maximum around 200 300e∨/u and for ECM ≤ 10e∨/u it monotonically increases with decreasing the collision energy, reaching a value of 8 × 10^-13 cm^2 at ECM = 0.05 e∨/u. The ion-pair formation process in Si（3p^2 ^3PJ）＋H（1s） collisions has also been considered and its cross section in the considered energy range is very small （smaller than 10^-20 cm^2 in the energy region below 1 ke∨/u）.     

Oscillator strengths for 2 transitions of the lithium isoelectronic sequence

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 1s^22s state to highly excited levels (n 3 10n \geq 10) and the oscillator strength densities corresponding to the bound-free transitions are obtained.     

Stability of small Ni-Ti bimetallic clusters studied by density functional theory

The low-energy structures and the electronic and the magnetic properties of small NiNiNi$_{m}$Ti$_{n}$ clusters, lowest-energy structure, electronic and magnetic propertiesProject supported by the National Natural Science Foundation of China (Grant No.~10874039), and the Natural Science Foundation of Hebei Province of China (Grant Nos.~A2009000246 and 2009000243).3120A, 3640B, 2110K7/3/2009 12:00:00 AMThe low-energy structures and the electronic and the magnetic properties of small NiNiNi$_{m}$Ti$_{n}$ clusters, lowest-energy structure, electronic and magnetic propertiesProject supported by the National Natural Science Foundation of China (Grant No.~10874039), and the Natural Science Foundation of Hebei Province of China (Grant Nos.~A2009000246 and 2009000243).3120A, 3640B, 2110K7/3/2009 12:00:00 AMThe low-energy structures and the electronic and the magnetic properties of small Ni$_{n}$Ti$_{n}$ ($n=1$--$6$) and Ni$_{m}$Ti$_{n}$ ($1 \le n \le 4$, $1 \le m \le 4$, $n \ne m$) clusters are investigated by performing all-electron calculations based on density functional theory. Ground states and several isomers near the ground states are determined for these clusters. The results indicate that the growth of small Ni$_{m}$Ti$_{n}$ clusters prefers to form rich Ti--Ni and Ti--Ti bonds. When the percentage of titanium atoms is significantly greater than that of nickel atoms, the nickel atoms are most frequently found above the surface; in contrast, the titanium atoms prefer the bridging sites. A M\"{u}lliken spin population analysis indicates that the total spin of titanium-nickel clusters is not always zero.http://cpb.iphy.ac.cn/CN/10.1088/1674-1056/19/4/043102https://cpb.iphy.ac.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=111644NimTin;clusters;lowest-energy;structure;electronic;and;magnetic;propertiesThe low-energy structures and the electronic and the magnetic properties of small Nin Tin(n = 1-6) and Ni m Ti n(1 ≤ n ≤ 4,1 ≤ m ≤ 4,n ≠ m) clusters are investigated by performing all-electron calculations based on density functional theory.Ground states and several isomers near the ground states are determined for these clusters.The results indicate that the growth of small Ni m Ti n clusters prefers to form rich Ti-Ni and Ti-Ti bonds.When the percentage of titanium atoms is significantly greater than that of nickel atoms,the nickel atoms are most frequently found above the surface;in contrast,the titanium atoms prefer the bridging sites.A Mu¨lliken spin population analysis indicates that the total spin of titanium-nickel clusters is not always zero.