Aims.In this paper we report calculations for energy levels and radiative rates for transitions in Fe IX.
Methods: .The General purpose Relativistic Atomic Structure Package (grasp) has been adopted for the calculation of energy levels and radiative rates.
Results: .Energies for the lowest 360 levels, including those from the (1s^22s^22p^6) 3s^23p^6, 3s^23p^53d, 3s3p^63d, 3s^23p^43d^2, and 3s^23p^54ℓ configurations of Fe IX, are reported. Additionally, radiative rates, oscillator strengths, and line strengths are reported for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among these levels. Comparisons are made with the available results in the literature, and the accuracy of the present data is assessed. Finally, lifetimes for all excited levels are listed, and comparisons made with earlier available measurements and theoretical results.