Improved nonrelativistic energies for 1s22psystems using a restricted variation method

Chung, Kwong T.; Zhu, X. W.

doi:10.1088/0031-8949/48/3/007

Cited by 41 publications

(30 citation statements)

References 30 publications

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“…(1) is restricted to being a single term, N, 's are basis functions similar to those of 4'b but with different nonlinear parameters. The advantage of 4 is that if the basis function in @, is very similar to that in %'&, no numerical instability will occur [30].…”

Section: Theorymentioning

confidence: 99%

“…For example, for [( ls 2p ) P, 3d ]2D', it is -8.938 -0.08 -0.238 = -9.26(20)cm (3) -9.02+ l.013 = -8.01 (20)cm (4) For [ls(2s2p) P] P' and [ls(2s2p) 'P] P', no well defined core is present. We take the average of 1s2s 'S, 1s2s S, 1s2p 'P, and 1s2p Pto give -9.02+0.22 = -8.80 (30)cm…”

Section: Theorymentioning

confidence: 99%

“…The restricted variation method [30] is one of these methods. It is an effective method of saturating the functional space with large numbers of basis functions but it avoids numerical instability.…”

Section: Introductionmentioning

confidence: 99%

“…It is an effective method of saturating the functional space with large numbers of basis functions but it avoids numerical instability. This method has been successfully applied to some three-and four-electron atomic systems [30,31]. It will be used in this work.…”

Section: Introductionmentioning

confidence: 99%

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Absolute term energy of core-excited doublet states of lithium

Chen

Chung

1994

Phys. Rev. A

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Thirteen core-excited lithium doublet states of the P, P', D, and D' symmetries are calculated with a multiconSguration-interaction wave function. A variation method is used for the bound states whereas the saddle-point and saddle-point complex-rotation methods are used for the autoionizing states. A restricted variation method is used for the saturated wave functions. Fine structures, relativistic corrections, and mass polarization corrections are calculated. The quantum electrodynamic corrections are also estimated. The absolute term energy is predicted with an uncertainty which is much smaller than that in the literature. Among these core-excited states, ten doublet-doublet transitions and one doubletquartet transition have been measured. The largest error bar for the transition energy has been 6.2 cm whereas others range from 0.5 to 3.3 cm . Our predicted transition wavelengths agree with the experiment for 10 of the 11 transitions. The only discrepancy is about 2 cm . In the case where there is a disagreement between different experiments, our results show a clear preference in the comparison. The transition rates calculated in this work suggest that other spectral lines may &iso be observed in future experiments.

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Section: Theorymentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Absolute term energy of core-excited doublet states of lithium

Chen

Chung

1994

Phys. Rev. A

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“…With the improvement of computing resources we can now perform much larger calculations to improve the accuracy. Computational methods such as the restricted variation method [10] have also been developed. Hence, the energies and widths of these resonances can be calculated to a much higher precision than before.…”

Section: Introductionmentioning

confidence: 99%

Energies and lifetimes of triply excited states of lithium

Chung

Gou

1995

Phys. Rev. A

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Nine triply excited states of lithium are calculated with the saddle-point and saddle-point complex-rotation methods. Relativistic corrections are computed with first-order perturbation theory. The widths are studied with one open channel at a time as well as fully coupled open channels. Some coupled calculations include up to ten open channels. Radiative decays of the triply excited states are also computed. The predicted Auger branching ratios are in excellent agreement with experiment. An identification is found for a weak line in the observed Auger spectra. Our predicted 2s2s2p P width is substantially smaller than the experiment of Kiernan et al. [Phys. Rev. Lett. 72, 2359 (1994)] but it agrees much better with the recent experiment of Kiernan et al. [J.

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Accurate nonrelativistic energies for2Po states of the Li isoelectronic series

Barrois

Kleindienst

Lüchow

1997

Int. J. Quant. Chem.

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Ž .With large Hylleraas᎐configuration interaction CI basis sets highly accurate upper bounds for the lowest 2 P o states of the Li isoelectronic series up to Ne are given. The corresponding Hamiltonian H and the operator Ý ٌٌ are transformed into i-j i j nonorthogonal coordinates expressed in interparticle and angular terms. The evaluation of the occurring integrals is reduced to the calculation of well-known auxiliary integrals. Furthermore some expectation values and isotope energies are calculated. The isotope energies are obtained using perturbation theory in first-order approximation.

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Improved nonrelativistic energies for 1s²2psystems using a restricted variation method

Cited by 41 publications

References 30 publications

Absolute term energy of core-excited doublet states of lithium

Absolute term energy of core-excited doublet states of lithium

Energies and lifetimes of triply excited states of lithium

Accurate nonrelativistic energies for2Po states of the Li isoelectronic series

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