Relativistic fine structure oscillator strengths for Li-like ions: C IV - Si XII, S XIV, Ar XVI, Ca XVIII, Ti XX, Cr XXII, and Ni XXVI
Department of Astronomy, The Ohio State University, Columbus, OH 43210, USA
Corresponding author: nahar@astronomy.ohio-state.edu
Received:
18
February
2002
Accepted:
30
April
2002
Ab initio calculations including relativistic effects in
the Breit-Pauli R-matrix (BPRM) method are reported for fine structure
energy levels and oscillator strengths upto 
and 
for 15 Li-like ions: C IV, N V, O VI, F VII, Ne VIII, Na IX,
Mg X, Al XI, Si XII, S XIV,
Ar XVI, Ca XIII, Ti XX, Cr XXII, and Ni XXVI.
About one hundred bound fine structure energy levels of total
angular momenta, 
of even and odd parities, total
orbital angular momentum, 
and spin multiplicity (2S + 1)
= 2, 4 are obtained for each ion. The levels provide almost 900
allowed
bound-bound transitions. The BPRM method
enables consideration of large set of transitions with uniform accuracy
compared to the best available theoretical methods. The CC eigenfunction
expansion for each ion includes the lowest 17 fine structure energy
levels of the core configurations 
, 
, 
, 
, 
,
and 
. The calculated energies of the ions agree with the measured
values to within 1% for most levels. The transition probabilities show
good agreement with the best available calculated values. The results
provide the largest sets of energy levels and transition rates for the
ions and are expected to be useful in the analysis of X-ray and EUV
spectra from astrophysical sources.
Key words: atomic data
© ESO, 2002