| Abstract: | Excitation energies from ground state for 86 fine-structure levels as well
as oscillator strengths and radiative decay rates for all fine-structure
transitions among the levels of the terms
(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) of Cr
XIII are calculated using extensive configuration-interaction
(CI) wave functions obtained with the CIV3 computer code of Hibbert. The
important relativistic effects in intermediate coupling are included through
the Breit-Pauli approximation via spin-orbit, spin-other-orbit, spin-spin,
Darwin and mass correction terms. Small adjustments to the diagonal elements
of the Hamiltonian matrices have been made. The mixing among several
fine-structure levels is found to be very strong. Our excitation energies,
including their ordering, are in excellent agreement (better than 0.5%)
with the available experimental results. From our transition probabilities,
we have also calculated radiative lifetimes of some fine-structure levels.
Our calculated lifetime for the longer-lived level 3s3p(3P1) is
found to be in excellent agreement with the experimental result of Curtis
compared to other theoretical calculations. |
