HARTREE–FOCK WAVE FUNCTIONS FOR EXCITED STATES: IV. OSCILLATOR STRENGTHS IN THE HELIUM ISOELECTRONIC SEQUENCE

1967 ◽  
Vol 45 (6) ◽  
pp. 2079-2090 ◽  
Author(s):  
Maurice Cohen ◽  
Paul S. Kelly
Keyword(s):  
Matrix Element ◽  
Excited States ◽  
Transition Matrix ◽  
Transition Matrix Element ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Hartree Fock ◽  
Good Agreement

Orbital wave functions for a number of singlet and triplet S, P, and D states of the helium sequence through C+4 have been calculated using an approximation described earlier. The wave functions have been employed to calculate the oscillator strengths for all allowed dipole transitions between these states, using both the length and velocity forms of the transition matrix element. Our results are in good agreement with the most accurate values available.

Theoretical ionization energies and oscillator strengths for the sodium isoelectronic sequence

1969 ◽  
Vol 47 (8) ◽  
pp. 835-838 ◽  
Author(s):  
R. P. McEachran ◽  
C. E. Tull ◽  
M. Cohen
Keyword(s):  
Matrix Element ◽  
Transition Matrix ◽  
Transition Matrix Element ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Ionization Energies ◽  
Core Approximation

Orbital wave functions for a number of 2S, 2P0, 2D, and 2F0 states of Na, Mg+, and Al2+ have been calculated by means of the frozen core approximation. The oscillator strengths of all allowed dipole transitions have been determined using both length and velocity formulations for the transition matrix element; these results agree with each other to within a few percent.

HARTREE–FOCK WAVE FUNCTIONS FOR EXCITED STATES: III. DIPOLE TRANSITIONS IN THREE-ELECTRON SYSTEMS

1967 ◽  
Vol 45 (5) ◽  
pp. 1661-1673 ◽  
Author(s):  
Maurice Cohen ◽  
Paul S. Kelly
Keyword(s):  
Excited States ◽  
Wave Functions ◽  
Electron Systems ◽  
Matrix Elements ◽  
Isoelectronic Sequence ◽  
Hartree Fock ◽  
Transition Matrix Elements ◽  
Simplified Procedure ◽  
Good Agreement ◽  
Dipole Length

Hartree–Fock wave functions for a number of S, P, and D states of the lithium isoelectronic sequence have been calculated, using a simplified procedure described in an earlier paper. Transition matrix elements for all permitted dipole transitions between these states have been computed using both the dipole length and the dipole velocity formulations. The results are in good agreement with earlier calculations.

Electric Quadrupole Transitions in Na I, Mg II and Al III

1972 ◽  
Vol 50 (11) ◽  
pp. 1169-1174 ◽  
Author(s):  
C. E. Tull ◽  
M. Jackson ◽  
R. P. McEachran ◽  
M. Cohen
Keyword(s):  
Electric Quadrupole ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Hartree Fock ◽  
Good Agreement

Theoretical multiplet strengths for electric quadrupole transitions between 2S, 2P0, 2D, and 2F0 levels of Na I, Mg II, and Al III have been calculated using Hartree–Fock wave functions of frozen-core type. The resulting 2S–2D oscillator strengths for Na I are in good agreement with calculations by Bogaard and Orr, Boyle and Murray, and Warner; however, for Mg II there is a discrepancy of a factor of 2 between our results and those of Warner.

Cancellation in the transition integrals for some dipole transitions: He isoelectronic series

1980 ◽  
Vol 58 (4) ◽  
pp. 546-548 ◽  
Author(s):  
Swadesh Kumar Ghoshal ◽  
Sankar Sengupta
Keyword(s):  
Confidence Level ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Hartree Fock ◽  
Isoelectronic Series

The amount of cancellation in the transition integrals for some np–n′d and nd–n′f singlet and triplet transitions for some members of helium isoelectronic sequence is estimated with Hartree–Fock wave functions. The results may act as a measure of the confidence level that can be attributed to the values of oscillator strengths of the respective cases.

scholarly journals Exchange effects in the absorption of light. I. Ca and Ca +

1941 ◽  
Vol 177 (970) ◽  
pp. 329-340 ◽  
Keyword(s):  
Matrix Element ◽  
Transition Matrix ◽  
Continuous Wave ◽  
Transition Matrix Element ◽  
Wave Functions ◽  
Absorption Coefficients ◽  
Continuous Absorption ◽  
Exchange Effects ◽  
Absorption Of Light ◽  
Theory And Experiment

The continuous absorption coefficients of normal Ca and Ca + are calculated. Both the discrete and continuous wave functions used in the calculation include the effect of electron exchange. Comparison is effected with results obtained neglecting exchange and it is found that appreciable modifications are introduced by its inclusion. This is particularly true for Ca + which is a sensitive case owing to very strong interference in the integrand of the transition matrix element. The bearing of the results on the calculation of absorption coefficients in general is discussed, and it is pointed out that the discrepancy between theory and experiment for potassium arises because this also is a very sensitive case. An application of the results for Ca is made to resolve a discrepancy between determinations of interstellar electron densities carried out using different methods by Strömgren and Struve.

An Exciton Approach to the Excited States of Two Electron Atoms. II. Determination of Spectroscopic Parameters, Polarizabilities and Dispersion Coefficients of H-, He, Li+, Be2+ and Ne8+

1985 ◽  
Vol 38 (1) ◽  
pp. 11
Author(s):  
PE Schipper ◽  
B Martire
Keyword(s):  
Excited States ◽  
Ground State ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Exciton Model ◽  
Interaction Coefficients ◽  
Isoelectronic Series ◽  
Helium Isoelectronic Series ◽  
Good Agreement

The exciton model developed in an earlier paper is applied quantitatively to a description of the excited states of representative members of the helium isoelectronic series; viz. H-, He, Li+,Be2+ and Ne8+. The energies of the eight lowest excited states are in good agreement with experiment, for a relatively small (1s-4p) hydrogenic basis; the ground state is obtained with slightly less precision. Response properties including oscillator strengths, polarizabilities and dispersion interaction coefficients are also calculated. The method appears to be quantitatively sound, and, above all, leads to particularly simple interpretations of the wave functions and the energies.

Systematic Trends in Atomic Oscillator Strengths: The Helium Isoelectronic Sequence

1972 ◽  
Vol 50 (12) ◽  
pp. 1363-1369 ◽  
Author(s):  
M. Cohen ◽  
R. P. McEachran
Keyword(s):  
Electric Dipole ◽  
Nuclear Charge ◽  
Principal Quantum Number ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Dipole Oscillator ◽  
Good Agreement ◽  
Comparison Data ◽  
Dipole Length

Electric dipole oscillator strengths (f values) have been calculated for a large number of singlet and triplet S–P, P–D, and D–F transitions in the helium isoelectronic sequence through O+6. The analytical orbital wave functions employed were of frozen-core type, and generally produce very good agreement between length and velocity values of the calculated oscillator strengths. A conspicuous exception occurs in many cases where the principal quantum number remains unchanged in the transition, and the more reliable dipole length values have been adopted for such transitions. The smooth variation of the calculated f values as functions of the inverse of the nuclear charge Z provided a sensitive check on the accuracy of the computations and indicated a considerable number of P–D transitions where the velocity values seemed the more reliable. Wherever comparison data are available, our calculated oscillator strengths are in excellent agreement with the most accurate values; in other cases, the absolute uncertainty in the f values should in no case exceed 5%.

Hartree-fock wave functions and oscillator strengths for the helium isoelectronic sequence

1976 ◽  
Vol 16 (1) ◽  
pp. 49-52
Author(s):  
D.K. Datta ◽  
S.K. Ghoshal ◽  
S. Sengupta
Keyword(s):  
Wave Functions ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
Hartree Fock

Oscillator strengths for highly stripped ions of carbon isoelectronic sequence

1995 ◽  
Vol 73 (9-10) ◽  
pp. 554-558 ◽  
Author(s):  
T. K. Ghosh ◽  
D. Ray ◽  
P. K. Mukherjee
Keyword(s):  
Oscillator Strength ◽  
Quantum Number ◽  
Excited States ◽  
Principal Quantum Number ◽  
Oscillator Strengths ◽  
Time Dependent ◽  
Isoelectronic Sequence ◽  
Hartree Fock ◽  
First Time

Time-dependent coupled Hartree–Fock theory was applied to estimate the allowed oscillator strengths of the astrophysically important highly stripped ions of the carbon isoelectronic sequence Ne4+, Mg6+, Si8+, S10+, Ar12+, Ca14+, and Ti16+ from their ground and valence-excited states up to principal quantum number n = 6. Oscillator-strength values compare favourably with the existing available data and many of the results are reported for the first time.

scholarly journals Current Status and Developments of the Atomic Database on Rare-Earths at Mons University (DREAM)

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18 ◽  
Author(s):  
Pascal Quinet ◽  
Patrick Palmeri
Keyword(s):  
Rare Earths ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Current Status ◽  
Time Resolved ◽  
Hartree Fock ◽  
Lanthanide Atoms ◽  
Experimental Values ◽  
Theoretical Results ◽  
Good Agreement

The main purpose of the Database on Rare Earths At Mons University (DREAM) is to provide the scientific community with updated spectroscopic parameters related to lanthanide atoms (Z = 57–71) in their lowest ionization stages. The radiative parameters (oscillator strengths and transitions probabilities) listed in the database have been obtained over the past 20 years by the Atomic Physics and Astrophysics group of Mons University, Belgium, thanks to a systematic and extensive use of the pseudo-relativistic Hartree-Fock (HFR) method modified for taking core-polarization and core-penetration effects into account. Most of these theoretical results have been validated by the good agreement obtained when comparing computed radiative lifetimes and accurate experimental values measured by the time-resolved laser-induced fluorescence technique. In the present paper, we report on the current status and developments of the database that gathers radiative parameters for more than 72,000 spectral lines in neutral, singly-, doubly-, and triply-ionized lanthanides.

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