Level energies, oscillator strengths, and lifetimes for transitions in Ti VI Man Mohan * , Avnindra K. Singh * , Alok K.S. Jha * , Pradip Jha Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India Available online 18 September 2006 Abstract We present an extensive, ab initio configuration interaction calculation of oscillator strengths, transition probabilities, and lifetimes of the upper levels of all transitions in Ti VI between the levels of 3s 2 3p 5 , 3s3p 6 , 3p 4 3d, 3p 4 4s, 3p 4 4p and 3p 4 4d states in the LSJ coupling scheme. Relativistic effects are incorporated by adding the mass correction, Darwin, and spin–orbit interaction terms to the non-relativ- istic Hamiltonian in the Breit–Pauli approximation. The calculations incorporate the major correlation effects. The calculated energy levels are in close agreement with most of the NIST tabulation. However, some discrepancies in the energy positions with experimental energies occur in levels with 3p 4 3d 1 D and 3 P cores, particularly belonging to 2 P and 2 D symmetries. We predict new data for several levels where no other theoretical and/or experimental results are available. Our extensive calculations will be useful to experimentalists in identifying the fine-structure levels in their future work. Ó 2006 Elsevier Inc. All rights reserved. 0092-640X/$ - see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.adt.2006.07.002 * Corresponding authors. Fax: +11 27667061. E-mail addresses: drmanmohan@vsnl.com (M. Mohan), avni_physics@rediffmail.com (A.K. Singh), aloksinghjha@yahoo.co.in (A.K.S. Jha). www.elsevier.com/locate/adt Atomic Data and Nuclear Data Tables 93 (2007) 105–126