Multiconfiguration Relativistic Random-phase Approximation Research Articles

Resonance transitions of Zn-like ions from the multiconfiguration relativistic random-phase approximation.

Excitation energies and oscillator strengths from the $^{1}$${\mathit{S}}_{0}$ ground state to the first $^{1}$P${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{1}$ and $^{3}$P${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{1}$ excited states of Zn-like ions are calculated by using the multiconfiguration relativistic random-phase approximation. Results are compared with those from other theories and with experiment. Predicted values for highly stripped ions are listed.

Relativistic excitation energies and oscillator strengths for the 6s2 1S0-->6s6p 1P1,3P1 transitions in Hg-like ions.

Excitation energies and oscillator strengths from the $^{1}$${\mathit{S}}_{0}$ ground state to the first $^{3}$${\mathit{P}}_{1}$ and $^{1}$${\mathit{P}}_{1}$ excited states of Cd-like ions are calculated by using the multiconfiguration relativistic random-phase approximation. Results are compared with other theories and with experiment. The discrepancy between the theoretical and experimental results is discussed.

Autoionizing levels of zinc from the multiconfiguration relativistic random-phase approximation.

Autoionizing levels of zinc from the multiconfiguration relativistic random-phase approximation.

Magnetic dipole transitions of Pb-like ions from the multiconfiguration relativistic random-phase approximation.

The multiconfiguration relativistic random-phase approximation theory is applied to magnetic dipole transitions in atoms. Excitation energies and oscillator strengths from the ground level $^{3}$${\mathit{P}}_{0}$ to the excited level $^{3}$${\mathit{P}}_{1}$ of Pb-like ions are calculated as prototypal examples. The first $^{3}$${\mathit{P}}_{1}$ level for the neutral Pb atom, which is missing in the relativistic random-phase approximation, appears naturally in this theory, which accounts for two-particle--two-hole correlations.

Autoionizing levels of beryllium from the multiconfiguration relativistic random-phase approximation.

Autoionizing levels of beryllium near its first ionization threshold are investigated using the multiconfiguration relativistic random-phase approximation. The 2pns $^{1}$P${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{1}$ and 2pnd $^{1}$P${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{1}$ Rydberg series of doubly excited states manifest as autoionization resonances in the 2s photoionization cross section. Theoretical predictions and available experimental data are in excellent agreement within 0.05 eV.

Resonance transitions of Mg- and Zn-like ions from multiconfiguration relativistic random-phase approximation

Multiconfiguration relativistic random-phase approximation has been developed to describe excitations of an atomic system having a multiconfiguration ground state. The response of such an atom to an imposed harmonic perturbation is determined by applying the time-dependent variational principle to a multiconfiguration wave function constructed from Dirac orbitais. Terms in the wave function independent of the external field lead to the multiconfiguration Dirac-Fock description of the ground state. Terms proportional to the external field lead to a multiconfiguration generalization of the relativistic random-phase approximation. Application of the multiconfiguration relativistic random-phase approximation theory to resonance transitions in Mg- and Zn-like ions are presented.

Resonance Transitions of Be-like Ions from Multiconfiguration Relativistic Random-Phase Approximation

Relativistic excitation energies and transition rates from the $^{1}S_{0}$ ground states to the first $^{3}P_{1}$ and $^{1}P_{1}$ excited states of berylliumlike ions are determined by using the newly developed multiconfiguration relativistic random-phase approximation (MCRRPA). Results from the MCRRPA theory are compared with those from other theories and experiments. The large discrepancies between the single-configuration RRPA predictions of excitation energies and the precise experimental values are resolved.