TRANSITIONS IN AR-II

We present extensive configuration iteraction (CI) calculations of osc illator strengths, transition probabilities and lifetimes of upper lev els of all transitions in Ar II between the levels of 3s(2)3p5, 3s3p6, 3p(4)3d, 3p(4)4s and 3p(4)4p states. The calculations incorporate the major correlation effects and in addition allow for the orbital funct ions (particularly 3p) to be effectively different for different state s. Some discrepancies with experimental energies remain, particularly those of levels with a 3p4 1S Core. Prior to the calculation of the os cillator strengths, we 'fine-tune' the ci coefficients using experimen tal energies. Specifically, the final CI coefficients are determined f ollowing small adjustments to the diagonal Hamiltonian matrix elements so that the calculated eigenvalue differences agree with the correspo nding experimental energy separations. This work describes in detail o ur previous calculations of quartet levels and extends the calculation s to other symmetries. Comparison with recent, highly accurate cascade -free experiments shows close accord in all but a small number of tran sitions.