No abstract

Energy levels, oscillator strengths and transition probabilities for transitions among the fine-structure levels of the terms belonging to the 3s 2 3p 2 , 3s3p 3 , 3s 2 3p3d, 3p 4 , 3s 2 3p4s, 3s 2 3p4p, 3s 2 3p4d and 3s 2 3p4f configurations of Ca VII are calculated using extensive configuration-interaction (CI) wavefunctions obtained with the CIV3 (configuration interaction version 3) computer code of Hibbert. The relativistic effects in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian which consists of the non-relativistic term plus the one-body mass correction, Darwin term, and spin-orbit, spin-other-orbit, and spin-spin operators. Small adjustments to the diagonal elements of the Hamiltonian matrices have been made, so that the energy splittings are as close as possible to the experimental values. The energy splitting of 70 fine-structure levels, oscillator strengths and transition probabilities for electric-dipole-allowed and intercombination transitions and, also the lifetimes of fine-structure levels are presented and compared with available experimental and other theoretical results. Our calculated fine-structure energies, including their ordering, show excellent agreement (better than 0.5%) with the available experimental results. In this calculation, we also predict new data for several levels where no other theoretical and experimental results are available.

We have calculated the excitation energies for the lowest 46 LS and 86 fine-structure levels as well as oscillator strengths and radiative decay rates for transitions among the (1s22s22p6)3s2(1S), 3s3p(1,3Po), 3s3d(1,3D), 3s4s(1,3S), 3s4p(1,3Po), 3s4d(1,3D), 3s4f(1,3Fo), 3p2(1S, 3P, 1D), 3p3d(1,3Po, 1,3Do, 1,3Fo), 3p4s(1,3Po), 3p4p(1,3S, 1,3P, 1,3D), 3p4d(1,3Po, 1,3Do, 1,3Fo), 3p4f(1,3D, 1,3F, 1,3G) and 3d2(1S, 3P, 1D, 3F, 1G) states in Ca IX. These states are represented by extensive configuration-interaction (CI) wavefunctions obtained with the CIV3 computer code of Hibbert. From our transition probabilities we have also calculated the radiative lifetimes of singlet and triplet states of Ca IX. Our results are compared with other available theoretical calculations and experimental data. To assess the importance of relativistic effects on our calculated values, we have also carried out calculations in the intermediate-coupling scheme. These effects are incorporated through the Breit-Pauli approximation via spin-orbit, spin-other-orbit, spin-spin, Darwin and mass correction terms. In order to keep our calculated energy splittings as close as possible to the experimental values, we have made small adjustments to the diagonal elements of the Hamiltonian matrices. The energy splittings of 87 fine-structure levels, the oscillator strengths and transition probabilities for some strong dipole-allowed and intercombination transitions and the lifetimes of some fine-structure levels are presented and compared with available experimental and other theoretical values. Our calculated lifetimes of the relatively long-lived 3p3d(3FJ) levels show remarkable improvement over the theoretical values of Fawcett, compared to the experimental results of Trabert et al. Also, our lifetime for the 3p2(1D2) level calculated in intermediate-coupling scheme, while differing significantly from our LS value, shows good agreement with the experimental value and thus confirms the need to include relativistic effects in calculations. In this calculation we also predict new data for several levels where no other theoretical and experimental results are available.

We have calculated the excitation energies, oscillator strengths and transition probabilities for electric-dipole-allowed and intercombination transitions among the 46 LS levels belonging to the configurations 3s 2 3p 2 , 3s3p 3 , 3s 2 3p3d, 3p 4 , 3s 2 3p4s, 3s 2 3p4p, 3s3p 2 ( 2 S)4s, 3s3p 2 ( 2 P)4s, 3s3p 2 ( 4 P)4s, 3s3p 2 ( 2 D)4s, 3s 2 3p4d and 3s 2 3p4f of Si-like Argon. These states are represented by extensive Configuration-Interaction (CI) wavefunctions obtained using the CIV3 computer code of Hibbert. From our transition probabilities we have also calculated the radiative lifetimes of singlet and triplet states of Ar V. Our results are compared with other available theoretical calculations and experimental data. To assess the importance of relativistic effects on our calculated values, we have also carried out calculations in the intermediate-coupling scheme using the Breit-Pauli Hamiltonian. Small adjustments to the diagonal elements of the Hamiltonian matrices have been made so that the energy splittings are as close as possible to the experimentally compiled energy values of the National Institute for standards and Technology (NIST). The energy splitting of 85 fine-structure levels, the oscillator strengths and transition probabilities for electric-dipole-allowed and intercombination transitions and the lifetimes of some finestructure levels are presented and compared with available experimental and other theoretical values. In this calculation, we also predict new data for several fine-structure levels where no other theoretical and experimental results are available.

We have performed large-scale CIV3 calculations of excitation energies from the ground state for 48 fine-structure levels as well as of oscillator strengths and radiative decay rates for all electric-dipole-allowed and intercombination transitions among the (1s22s22p6)3s2(1S), 3s3p(1,3Po), 3s3d(1,3D), 3s4s(1,3S), 3s4p(1,3Po), 3s4d(1,3D), 3s4f(1,3Fo), 3p2(1S, 3P, 1D), 3p3d(1,3Po, 1,3Do, 1,3Fo), 3p4s(1,3Po) and 3d2(1S, 3P, 1D) states of Br XXIV. These states are represented by extensive configuration-interaction (CI) wavefunctions obtained using the CIV3 computer code of Hibbert. The relativistic effects in intermediate coupling are incorporated by means of the Breit–Pauli Hamiltonian which consists of the non-relativistic term plus the one-body mass correction, Darwin term, and spin–orbit, spin-other-orbit and spin–spin operators. Small adjustments to the diagonal elements of the Hamiltonian matrices have been made so that the energy splittings are as close as possible to the experimental values. Our calculated excitation energies, including their ordering, are in excellent agreement with the available experimental results except that the levels 1D2 and 3P2 belonging to the same configuration 3p2 interchanged their positions compared to the experiment. This interchange in our calculation is discussed and explained through eigenvector compositions of the two levels. From our radiative decay rates, we have calculated radiative lifetimes of some fine-structure levels. Our calculated lifetimes of the levels 3s3p(3P1) and 3s3p(1P1) are found to be in good agreement with the experimental and other theoretical results. In this calculation we also predict new data for several fine-structure levels where no other theoretical and experimental results are available.