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.

Quintet States 1s2s2p2 5P and 1s2p3 5So for Be-Like Systems

2019 ◽  
Vol 74 (9) ◽  
pp. 743-749
Author(s):  
Kai Kai Li ◽  
Lin Zhuo ◽  
Yan Sun ◽  
Bing Cong Gou
Keyword(s):  
Variational Method ◽  
Excited States ◽  
Relativistic Effect ◽  
Oscillator Strengths ◽  
Isoelectronic Sequence ◽  
The Core ◽  
Transition Wavelength ◽  
Computational Data ◽  
First Time ◽  
Hyperfine Structures

AbstractBy systematic Rayleigh–Ritz variation calculations, the energies are reported for the core-excited states 1s2s2p2 5P and 1s2p3 5So in the Be-like isoelectronic sequence (Z = 11–20). Energy corrections, including the restricted variational method, mass polarisation, and relativistic effect, are considered to improve the accuracy of energy. The oscillator strengths and transition wavelength between these states are also reported. Computational data on hyperfine structures presented in this paper are calculated for the first time.

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.

ENERGY, OSCILLATOR STRENGTH AND HYPERFINE STRUCTURE OF THE LOW-LYING EXCITED STATES FOR Be-LIKE SYSTEM

2003 ◽  
Vol 14 (05) ◽  
pp. 549-560 ◽  
Author(s):  
FEI WANG ◽  
BINGCONG GOU ◽  
XIAOLI WU ◽  
LIHONG HAN
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Variational Method ◽  
Hyperfine Structure ◽  
Oscillator Strength ◽  
Excited States ◽  
Oscillator Strengths ◽  
Transition Rates ◽  
Isoelectronic Sequence ◽  
Relativistic Corrections

The Rayleigh–Ritz variational method is carried out with a multiconfiguration-interaction wave function and restricted variational method to obtain the relativistic energies of the 1s22s2p 1Po , 1s22s2p 3Po , and 1s22p23P states for the beryllium-like isoelectronic sequence (Z=4–10), including the mass polarization and relativistic corrections. The oscillator strengths and transition rates are also calculated. The results are compared with other theoretical and experimental data in the literature. The hyperfine structure of the low-lying excited states for this system is also explored.

Transitions between excited states of two-electron systems in time-dependent hartree-fock theory

1980 ◽  
Vol 76 (2) ◽  
pp. 287-290 ◽  
Author(s):  
M.J. Jamieson ◽  
R.S. Watts
Keyword(s):  
Excited States ◽  
Time Dependent ◽  
Electron Systems ◽  
Hartree Fock

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 Chebyshev matrix product states with canonical orthogonalization for spectral functions of strongly correlated systems

2021 ◽  
Author(s):  
Tong Jiang ◽  
Jiajun Ren ◽  
Zhigang Shuai
Keyword(s):  
Excited States ◽  
Strongly Correlated Systems ◽  
Time Dependent ◽  
Matrix Product ◽  
Strongly Correlated ◽  
Effective Hamiltonian ◽  
Spectral Functions ◽  
Correlated Systems ◽  
Matrix Product States ◽  
First Time

We propose a method to calculate the spectral functions of strongly correlated systems by Chebyshev expansion in the framework of matrix product states coupled with canonical orthogonalization (coCheMPS). The canonical orthogonalization can improve the accuracy and efficiency significantly because the orthogonalized Chebyshev vectors can provide an ideal basis for constructing the effective Hamiltonian in which the exact recurrence relation can be retained. In addition, not only the spectral function but also the excited states and eigen energies can be directly calculated, which is usually impossible for other MPS-based methods such as time-dependent formalism or correction vector. The remarkable accuracy and efficiency of coCheMPS over other methods are demonstrated by calculating the spectral functions of spin chain and ab initio hydrogen chain. We demonstrate for the first time that Chebyshev MPS can be used in quantum chemistry. We also caution the application for electron-phonon system with densed density of states.

Atomic structure and radiative properties of He-like Ni26+ ion in dense plasma

2021 ◽  
Author(s):  
Mayank Dimri ◽  
Dishu Dawra ◽  
A.K. Singh ◽  
Alok K.S. Jha ◽  
Rakesh Kumar Pandey ◽  
...  
Keyword(s):  
Quantum Number ◽  
Transition Probabilities ◽  
Principal Quantum Number ◽  
Model Potential ◽  
Oscillator Strengths ◽  
Radiative Properties ◽  
Configuration Interaction Method ◽  
Excitation Energies ◽  
Plasma Energy ◽  
Plasma Background

The influence of plasma screening on the excitation energies and transition properties of He-like Ni<sup>26+</sup> ion under strongly coupled plasma background has been analyzed. To perform the analysis, the multiconfiguration Dirac-Fock method has been adopted by incorporating the ion sphere model potential as a modified interaction potential between the electron and the nucleus. For comparison purposes, parallel calculations have been carried out using the modified relativistic configuration interaction method. It is found that the plasma energy shifts corresponding to principal quantum number conserving transitions (Δ n = 0) are blue shifted, whereas red shifted for the transitions where the principal quantum number is not conserved (Δn ≠ 0). The variation of transition probabilities and weighted oscillator strengths with free electron densities has also been studied. The present results should be advantageous in the modeling and diagnostics of astrophysical and laboratory plasmas.

scholarly journals Multiresolution quantum chemistry in multiwavelet bases: excited states from time-dependent Hartree–Fock and density functional theory via linear response

2015 ◽  
Vol 17 (47) ◽  
pp. 31405-31416 ◽  
Author(s):  
Takeshi Yanai ◽  
George I. Fann ◽  
Gregory Beylkin ◽  
Robert J. Harrison
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemistry ◽  
Numerical Method ◽  
Excited States ◽  
Multiresolution Analysis ◽  
Linear Response ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Hartree Fock

A fully numerical method for the time-dependent Hartree–Fock and density functional theory (TD-HF/DFT) with the Tamm–Dancoff (TD) approximation is presented in a multiresolution analysis (MRA) approach.

Multiconfiguration Dirac–Hartree–Fock calculations of energy levels, wavelengths, weighted oscillator strengths, transitions probabilities and lifetimes of Cd XLVII

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dhia Elhak Salhi ◽  
Soumaya Manai ◽  
Sirine Ben Nasr ◽  
Haikel Jelassi
Keyword(s):  
Missing Data ◽  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Accurate Data ◽  
Cadmium Ion ◽  
Hartree Fock ◽  
First Time ◽  
Good Agreement

Abstract Energy levels, wavelengths, weighted oscillator strengths, transition probabilities and lifetimes are calculated for all levels of 1s 2 and 1snl (n = 2–6) configurations of He-like cadmium ion (Cd XLVII). The calculations were carried out using three codes GRASP2018, FAC and AMBiT in order to provide theoretically the most accurate data. Transition probabilities are reported for all the E1, E2, M1 and M2 transitions. Breit interactions and quantum electrodynamics effects are included in the RCI calculations. Comparisons were made with other calculations and a good agreement was found which confirms the reliability of our results. We present some missing data for the He-like cadmium in this paper for the first time.

A time-dependent Hartree-Fock study of the neon isoelectronic sequence

1975 ◽  
Vol 29 (5) ◽  
pp. 1577-1583 ◽  
Author(s):  
Ronald F. Stewart
Keyword(s):  
Time Dependent ◽  
Isoelectronic Sequence ◽  
Hartree Fock
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