On the accuracy of the Coulomb approximation and a model-potential method for atomic transition probabilities in alkali-like systems

1992 ◽  
Vol 45 (3) ◽  
pp. 238-245 ◽  
Author(s):  
C Laughlin
Keyword(s):  
Transition Probabilities ◽  
Potential Method ◽  
Model Potential ◽  
Atomic Transition ◽  
Coulomb Approximation

scholarly journals Emission Lines of CI and N II in Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 225-225
Author(s):  
V. Escalante
Keyword(s):  
Radiative Recombination ◽  
Transition Probabilities ◽  
Potential Method ◽  
Dielectronic Recombination ◽  
Model Potential ◽  
Emission Lines ◽  
Published Data ◽  
Recombination Rates ◽  
Doubly Excited ◽  
Ngc 7027

A model potential method (Caves and Dalgarno, 1972, J. Quant. Spect. Rad. Transf., 12, 1539) was used to calculate accurate non-hydrogenic radiative recombination rates and transition probabilities of singly excited states of CI and N II. The results can be used to determine the excitation mechanism of emission lines and to estimate N III concentrations in nebulae with CI and N II emission lines. In most nebulae, observed permitted lines of N II are produced by radiative recombination, but sometimes stronger recombination lines are missing in their spectra. The [CI] lines observed in NGC 7027 cannot be explained by simple radiative and dielectronic recombination. The low [CI] λλ9850 + 23/ λ8727 value may indicate that the emission is produced in high density (NeZ 105 cm−3) condensations where partial collisional deexcitation of metastable levels, takes place. N III concentrations were determined using published data of NGC 3242, NGC 3918, and NGC 6572. The procedure outlined by Wilkes et al. (1981, M.N.R.A.S., 197, 1) to determine N abundances from (N+ + N++)/He+ ratios does not always give consistent results with UV or [N II] data. The problem may be due to errors in the calculation of transition probabilities involving the doubly excited levels 2s2p33P0 and 3D0 of N II that affect the branching and effective recombination rate of the multiplet N II λ5680.

Atomic transition probabilities of Ce I from Fourier transform spectra

2010 ◽  
Vol 43 (8) ◽  
pp. 085701 ◽  
Author(s):  
J E Lawler ◽  
J Chisholm ◽  
D E Nitz ◽  
M P Wood ◽  
J Sobeck ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Transition Probabilities ◽  
Atomic Transition ◽  
Fourier Transform Spectra

Calculation of Pairwise Effective Potentials in the Disordered Ni-22.5at.%Fe Alloy Using Model Potential Method with Account of Size Effect

2021 ◽  
Vol 323 ◽  
pp. 125-129
Author(s):  
Valentin Silonov ◽  
Lkhamsuren Enkhtor
Keyword(s):  
Size Effect ◽  
Short Range ◽  
Short Range Order ◽  
Potential Method ◽  
Model Potential ◽  
Order Parameters ◽  
Range Order ◽  
Disorder Phase Transition ◽  
Effective Potentials ◽  
Atomic Displacements

Pairwise effective potentials in first seventeen shells of the Ni-22.5at.%Fe alloy are calculated using model potential method with account of the linear size effect. Using obtained values of pairwise effective potentials, the short range order parameters on the first seventeen shells of alloy are calculated by Krivoglaz-Clapp-Moss method. The calculated values ​​of the short-range order parameters were fitted to the experimental values ​​by varying the parameters of static atomic displacements. Reliable value of critical temperature of order-disorder phase transition in Ni-22.5at.%Fe alloy was calculated using obtained meanings of pairwise effective potentials.

scholarly journals The ab initio model potential method with the spin-free relativistic scheme by eliminating small components Hamiltonian

2001 ◽  
Vol 114 (14) ◽  
pp. 6000-6006 ◽  
Author(s):  
Kyosuke Motegi ◽  
Takahito Nakajima ◽  
Kimihiko Hirao ◽  
Luis Seijo
Keyword(s):  
Ab Initio ◽  
Potential Method ◽  
Model Potential

Atomic transition probabilities of Nd I

2011 ◽  
Vol 44 (23) ◽  
pp. 235003 ◽  
Author(s):  
M H Stockett ◽  
M P Wood ◽  
E A Den Hartog ◽  
J E Lawler
Keyword(s):  
Transition Probabilities ◽  
Atomic Transition
Sign in / Sign up

Export Citation Format

Share Document